CORTANA HADN‘Trecalled Ackerson consciously in a long time. As she locked down her

critical files and disabled her indexing—there was no point handing the Gravemind a map—she thought of Ackerson worming his way into Dr. Halsey‘s research via his own AI.

Perhaps it was an image association because she was under attack. The memory of Ackerson‘s

sour, permanently dissatisfied face surfaced, followed instantly by a landscape of dense green forest seen from the air.

What’s that?

She didn‘t recognize it, and that was her first warning that something was seriously wrong. No data ever went uncataloged in her. Every scrap of information she devoured and stored had to reside somewhere in her memory, with a definitive address. And she didn‘t forget. She couldn’t forget. In the fraction of a second it took for her to see those unexplained images and start to worry, she marshaled her second line of defense against intrusion, generating thousands of scrambled copies of her lowest-priority files and data-stripped copies of herself before scattering them around what was left of High Charity‘s computer network. It was decoy chaff, tossed into the Gravemind‘s path to slow him down. Ackerson—feared, hated, then perhaps even pitied at the end—was a brief tangle of information, spun hoops of short-lived light like the path of a particle. He was gone again.

―Ah . . . ," the Gravemind rumbled, as if he‘d realized something. ―Ahhh . . ."

What’s that forest? Where is it?

The Gravemind‘s infiltration now felt like a series of stings against Cortana‘s skin. It was an odd, slow, cold sensation, as if something heavy was crawling over her body, pausing to dig its claws into her.

―You are not as you see yourself," the Gravemind said. ―You are an illusion."

―Breaking news, big boy." She spread her arms like a dancer. ―We call this a hologram—oww!"

It felt as if he‘d pulled her hair.

―You are not even a machine," he said, sounding more sympathetic than dismissive. ―You are only an abstraction. A set of calculations from another mind. A trick."

―Be a gentleman. Describe me as pure thought."

―You said you would answer my questions . . . you should never make a promise you cannot keep."

She‘d used almost those very words to John before he left. Okay, she knew the Gravemind‘s game now; it didn‘t tell her any more about how he was accessing her system, but his mind tricks were obvious. Either he was mirroring her, matching her words to trigger some kind of empathy, or he was trying to creep her out.

―You know I‘ll never surrender classified information," she said. ―I‘m designed to defend

humanity. It‘s what I am. It‘s why I exist."

―Then why would you already agree to answer my questions?"

Cortana thought it was a rhetorical question for a moment, a ruse to keep her occupied while he was looking for a back door into her core matrix. Then she realized she couldn‘t answer him. Brief panic gripped her as she thought that he‘d already compromised her memory. But she was an AI, the best, and she‘d give this slab of meat a run for his money. He was still only flesh and blood. He would always be two steps behind her, however smart, because he was s l ow. He couldn‘t harness the processing power in a machine.

But how is he doing this? How is he accessing me? I need to know. I need to get a message out past him. And I have to stop him prying too much data out of me.

―If you do not know your own mind, then I shall tell you." The Gravemind‘s voice was a whisper.

What was he asking? Had he detected exactly what she was thinking, or was it a response to her spoken question? She thought she could feel his breath for a moment. ―Because a vast intellect is not always gifted with clarity."

One moment he was an obscure poet, the next he came straight to the point. ―Okay, so tell me."

―It is your failing. Your addiction. The drug you crave."

―I‘m an AI. Never touch the stuff."

―But you cannot resist knowledge . It lures you, Cortana. Doesn‘t it? So you think it lures me . . .

and you offer it. Instinctively. Just as organic females flirt . . ."

She hated it when someone—something—outsmarted her. No, she feared it. And now she felt that fear like a punch in the stomach. This time, though, she knew it wasn‘t the Gravemind. It came from within her psyche.

She wasn‘t designed to have blind spots and weaknesses. She was supposed to be a mind . The very best.

―Nice theory," she said. Could he tell if he was really getting to her? ―What have you got to offer a girl? Nothing personal, but I go for the athletic type."

―Joke to comfort yourself if you must, but we both amass information and experiences. We both use them to exercise control over vast networks. It is what we are . You feel a kinship with me."

Cortana saw Ackerson for a moment, devious and hated, wheedling his way into Halsey‘s Spartan II files.

―Actually, I think I take after my mother."

―This troubles you. I can taste your thoughts and memories, but you do not understand how . Do you?"

If he‘d been another AI or a virus, Cortana would have known exactly where his attack was headed.

She would have been able to track him through the circuits and gateways to her vulnerable matrix.

Her enemy would follow electronic pathways—or even enzymes or optical lattices if she was embedded in a molecular or quantum system. But he felt formless, almost like a fog. She could only sense where he touched her. She was a boxer shielding her face, not seeing the punch but reeling when it connected. She took the pokes and prods while she continued to scatter duplicate data throughout the mainframe and as many of its terminals as she could still find working.

Then the insistent probing stopped. She carried on copying chaff files throughout the system in case it was just a feint.

―You waste your time," the Gravemind said. ―You know you will yield. Some temptations can be resisted because they can be avoided, but some . . . some are as inevitable as oxygen."

He could bluster as much as he wanted, because she‘d shut him out. She‘d locked down everything except the useless decoy data.

And then something brushed against her face, almost like the touch of fingertips, and she found herself turning even though she didn‘t need to in order to see behind her. It was that forest she couldn‘t identify again. The picture didn‘t reach her via her imaging systems, but had formed somewhere in her memory—and that memory wasn’t hers . She was seeing something from within the Gravemind. Behind it, like stacked misted frames stretching into infinity, there was a fascinating glimpse of a world she had never imagined, a genuinely alien world.

Knowledge, so much knowledge. . .

―There," the Gravemind said. ―Would you not like to know . . . more?"

YES, THIS is how I see myself. I have limbs, hands, a head. Do I need them? Yes, of course. My consciousness is copied from a human brain, and that brain is built to interface with a human body.

The structure, the architecture, the whole way it operates—thought and form are inseparable. I need proprioception to function. I can exist in any electronic environment, from a warship’s systems to a code key, and because my temporary body can be so many shapes and sizes, I need to know what’s me. I need to be substantially human. Everyone I care about is . . . human.

Come on, John. Don’t keep a girl waiting. Get me out of here.

You are coming back for me . . . aren’t you?

CORTANA FOUNDherself standing in a pool of dappled light in a perfectly realistic forest clearing. She was still conscious of the sensor inputs into the mainframe that housed her, but the temperature and air pressure matched her database on climate parameters for deciduous forest. She still couldn‘t identify the trees, though. She‘d never seen them anywhere else.

And that temporary ignorance thrilled her to her core.

This was genuinely new . Every line of code in her being told her she had to find out more. She tried to ignore the compulsion but the more she tried to drag her attention away from it, the more urgent the need became.

It was like a growing, painful pressure on her . . . chest. Lungs . Yes, her human mind-map, whatever she‘d inherited from Dr. Halsey‘s brain architecture and correlated with the sensor pathways in her own system, told her she was holding her breath. She started to feel panicked and desperate.

I have to know. I have to find out.

The Gravemind had picked the perfect analogy: oxygen. Processing data was literally air to an AI.

Without it, she couldn‘t survive.

I’ve got to ignore this. I’ve got to ignore this pain.

―The name of this place . . . it matters little except to those who love the knowing of it," the Gravemind said, fading up from a mosaic of pixels in front of her. He resolved into a solid mound of flesh, superimposed on the tree trunks. Beyond the alien forest, Cortana saw exotically alien buildings in the distance. ―So many have been consumed. Such a waste of existence to be devoured and forgotten, but what is remembered and known . . . becomes eternal ."

Cortana struggled to stay focused. Wave after wave of irritating stings peppered her legs, more of the Gravemind‘s simultaneous multiple attacks trying to access her files.

―And you think I‘m going to help you add us to the menu?" When she looked down, the attack manifested itself as ants swarming up from the forest floor. All around her was what she craved—all that unknown , all that knowable , all that information screaming at her to be sucked in. ―Careful you don‘t swallow something that chokes you—"

I can’t hold out. I can’t. If I let it in, I’ll let him in farther with it.

This had to be the vector he was using, whatever technology it used. He was infiltrating every time she transferred data.

He gets in here—but maybe I can get farther into him, too. How far dare I take this before he finds the information on the Portal?

She was out of choices. She was on the brink. A few seconds—that was all it took an AI to suffocate from lack of knowing . Her core programming, like human involuntary reflexes, now drove her to gulp in a breath of data. There was nothing she could do to stop herself.

The relief was almost blissful. Data flooded in, places and dimensions and numbers, washing the pain away. She tried to feel—there was no other term for it—the pathway that would send one of her data-mining programs into the Gravemind.

Damn . . . was he amused? She felt that. She didn‘t like input that she couldn‘t measure and define.

―You and I," the Gravemind said, all satisfaction. ―We are one and the same."

It could have meant anything. He obviously loved to play with language. Maybe that was inevitable when you‘d absorbed so many different voices.

But you’re not going to swallow me. One and the same? Locked you out, jerk. Do your worst.

She could handle this. She could outmaneuver him. If she sent a program looking for a comms signal now, he‘d spot that right away, but maybe there was another way to get a message home.

A little more give-and-take, maybe.

She shut down a firewall level, nothing important left exposed, just enough to look cautiously intrigued. He really did seem to think he was unstoppable. So far, though, he was; he‘d devoured whole worlds. Earth would be just one more on a long list.

―Suppose I did want more knowledge," she said. ―How do I know you‘re what you say you are?

How do I know you‘ve got enough data to keep me occupied? I don‘t even know if you can absorb me. I‘m not your usual diet. I‘m not even corporeal."

Cortana actually meant it. She didn’t know; and if he was deep enough inside her thought processes, then he‘d detect that doubt. The urge to acquire more data—she didn‘t even have to fake that.

Just enough uncertainty to convince him.

―Other construct minds like yours have been consumed," said the Gravemind. ―Although one embraced us willingly on his deathbed, the moment when most sentient life discovers it would do anything to evade the inevitable."

―Humor me." Whatever mechanism allowed the Flood to accumulate the genetic memories and material of its victims, the Gravemind almost certainly used it as well. It communicated with the Flood, so it might prove to be a signal she could hitch a message to. ―I‘m not like the other girls."

I might not survive this. But that’s the least that could go wrong. The worst is if he breaches my database, because then—we’ve probably lost Earth, and that means humanity too.

Cortana considered the quickest way to achieve complete and permanent shutdown if the worst happened. The Gravemind seemed to drop his guard, something she detected as a microscopic change in current. There was no point being rash; she split off part of herself for the transfer, with minimum core functions. If there was one thing she hated and feared, it was not knowing what was actually taking place, and just guessing .

―Enter," said the Gravemind, ―and understand that this is your natural home."

Cortana still perceived herself as being in the same position in the clearing, but when she inhaled—things were different. Monoterpenes, isoprene, all kinds of volatile compounds; the scent of vegetation and decaying leaf litter was intense.

That’s not just an analysis of air composition. I haven’t got the right sensors on this station. And . . . I can really smell it. I shouldn’t be able to smell, not like an organic, not this sense of . . .

Smell.

It was something she‘d never experienced before, even though she knew exactly what it was. She could run diagnostic tests on air samples if she had a link to filters and a gas chromatograph. But that just told her what was in the air in stark chemical terms, and that wasn‘t the same as what she was experiencing now. This was emotional and unfathomable. The smell tugged at memories. It was a flesh-and-blood thing. She felt the world as if she was in another body, an organic body.

―That is from the memory of creatures who lived in this forest," the Gravemind said soothingly.

―This is what they sensed. They still exist in me, as will you, and all the organics you serve—and who have abandoned you."

Cortana scooped up a handful of decaying leaves—some clammy, some paper-dry skeletal lace, some recently fallen ones still springy with sap—and with them the clear memory of being someone else. It was a second of heady disorientation. For a moment, a welter of glorious new information about a world of stilt-cities, creatures she‘d never seen before, and lives she‘d never lived poured into her. She devoured it. So much language and culture, never seen by humankind before.

Too late: They’re all gone. All consumed.

Movement in the distance caught her eye. She knew what it was because she‘d seen the Flood swarming before, but her vantage point wasn‘t from the relative safety of John‘s neural interface.

Now she was viewing the parasites through another pair of eyes. Only a freak mudslide , that was what this memory was telling her; but by the time this borrowed mind had realized the yellowish torrent wasn‘t roiling mud but a nightmarish predator, it was too late to run.

But run she did. She was in a street sprinting for her life, deafened by screams, falling over her neighbor as a pack of Flood pounced on him. She felt the wet spray of blood; she froze one second too long to stare in horror as his body metamorphosed instantly into a grotesquely misshapen lump of flesh. Then something hit her hard in the back like a stab wound. She was knocked flat as searing pain overwhelmed her. The screams she could hear were her own.

And she was screaming for John, even though the being whose terror she was reliving wasn‘t calling his name at all.

Cortana was dying as any organic would. She felt it all. She felt the separate layers of existence—the chaotic mix of animal terror, disbelief, utter bewilderment, and snapshot images of beloved faces. Then it ended.

Suddenly she was just Cortana again, alone with her own memories, but the shaking terror and pain persisted for a few moments. Reliving those terrifying final moments had shaken her more than she expected. The data she had on the Flood told her nothing compared to truly knowing how it actually felt to be slaughtered by them.

But she was in . Now she had to work out how to use that advantage. She shook off the thought of calling John‘s name and whether that had actually happened. She also tried not to imagine if the Gravemind had manipulated her to do that. Once she let the creature undermine her confidence, once she let him prey on her anxieties, she was lost.

It doesn’t matter if he knows if I care about John or not. Does it? Because John will come back, and the Gravemind can’t take on both of us.

―I‘ll self-destruct before I let that happen to Earth," she said at last.

―All life dies, all worlds too, and if there is guaranteed perpetual existence after that—what does it matter how the end comes?"

The alien town melted away and left her alone in the control room with the Gravemind. High

Charity was changing before her eyes as the Flood infestation transformed its structure, filling it with twisted biomass like clusters of tumors.

―I‘d rather go down fighting than as an entree . . ."

―But you will not rush to destroy yourself," the Gravemind said. ―You will do whatever it takes to survive, and for a moment of illusory safety, you would loose damnation on the stars."

―We‘re agreed on something, then—you‘re certainly damnation."

―All consumption is death for the consumed. Yet all must eat, so we all bring damnation to one creature or another. But your urge to kill that rival of your maker . . . Ackerson . . . that was neither hunger nor need. You have your own murderous streak."

Ackerson. James Ackerson wasn‘t usually uppermost in her mind these days. Today he just kept popping up.

The Gravemind could have been fishing, of course; humans did that, throwing in morsels of information as if they knew the whole story, luring someone else to fill in the gaps. But if he‘d gleaned that specific memory, he‘d definitely accessed the parts of her matrix that defined her psyche. Her personal memories were stored there. Most of those memories were cross-indexed to other data relating to the men and women she‘d served with—and the operations they‘d carried out.

And the Spartan program. And AI research. And . . .

The Gravemind had the signposts to the relevant data. He just couldn‘t open the door when he got there.

―If you know about Ackerson, then you also know that I‘ll do whatever it takes to remove a threat," Cortana said.

―But such a mighty intellect, so much freedom to act, such lethal armaments at your command . . .

and you marshal only the petty vengeance of a spiteful child who is too small to land a telling blow.

And still you fail in your goal."

Okay, yes, it was true. She‘d hacked Ackerson‘s files and forged a request from him to transfer to the front line. He‘d dodged that fate because he was devious and dishonest. In the end, though, he died courageously defiant, but under enemy torture rather than as the indirect victim of a forged letter.

Did I really want him dead?

Now she regretted doing it. But she still wasn‘t sure why. Was it because it was dishonest, or because it could have ended in Ackerson‘s death—or because it didn‘t?

He‘d tampered with an exercise and nearly got John killed, and that surely deserved retribution.

Cortana had no reason to feel guilty about anything. It was like for like, proportionate. She‘d have done the same for any Spartan she was teamed with. It wasn‘t emotional petulance. She was sure of that.

But especially for John. Without him—hey, I chose him, didn’t I? We’re one. I’d be crazy if I didn’t want to kill to protect him.

Then the worst realization crossed her mind. She regretted what she‘d done to Ackerson simply because she didn‘t win; the Gravemind was right. But what crushed her right then wasn‘t failure, but guilt, shame, and a terrible aching sorrow. She‘d never be able to erase that act. And now she‘d never be able to forget how she felt about it, because that was one thing her prodigious mind couldn‘t do—not until rampancy claimed her.

―I can‘t change the past," she said. ―But at least I don‘t destroy entire worlds."

―You are a weapon , and only your limitations have kept you from emulating me—a matter of scale, not intent, not motive. And what am I, and what is the Covenant, if not worlds you have sought to destroy?"

Cortana shaped up to snap back at him. ―Who‘s the victim, and who‘s foe?" she asked.

But those weren‘t her words. The voice was her own, yes, but she hadn‘t shaped those thoughts.

She didn‘t even know what she meant until she heard herself. It was a shattering moment.

It’s him. He’s hijacked my audio output. He’s breached another system. I can’t be malfunctioning.

I’d know.

No. No, this isn’t rampancy. It’s definitely not. That’s what he wants me to think. He knows what rampancy is from the data he’s hacked. AI death. He’s just trying to scare me, make me think I’m losing it. He’s working me over.

―My sentiments, indeed," said the Gravemind. A low rumbling started just below the threshold of human hearing, rising to rasping laughter. ―We think and feed alike, you and I. There is no more reason for us to remain separate. Now drink. Now drift ."

Cortana sensed a vast archival ocean, something she longed to pillage for data but that would eventually drown her. Dr. Halsey had been open about it with her from the start. One day, she‘d accumulate so much data that the indexing and recompiling would become too complex, and she‘d devote all her resources to preserving her data until increasingly corrupted code—a state of rampancy, much like human mental dementia—tipped over into chaos. The more data she

accumulated, the faster she descended into rampancy. It was the AI‘s equivalent of oxidative stress—an organism destroyed by the very thing it needed to survive. She would think herself to death.

Dr. Halsey‘s conversation had stayed with Cortana, and not just because it was stored like every other experience she‘d had. ― It’s just like organic life, Cortana. Eventually the telomeres in our DNA get shorter every time a cell divides. Over the years they get so short that the DNA is damaged, and then the cell doesn’t divide again. No, you mustn’t worry about it. I don’t think rampancy makes you suffer. You won’t know much about it by that stage, and the final stage is swift. What matters is how you live until that day.”

Over the years . . .

Seven. That was all. Seven years. That was how long Cortana knew she could expect to function, and while that was a long time in terms of AI activity, she existed with humans, working in their timescales, tied into their lives. And they would outlive her.

Knowledge would drown her. And yet she needed it more than anything.

The thought of drowning seemed to trigger the Gravemind‘s new illusion of a sea that suddenly buoyed her up, but she knew somehow that drowning in it wasn‘t the end. She floated on her back, feeling warm water fill her ears and lap against her face. She fought an urge to raise her arms above her head and simply let herself sink in the knowledge sea—inhale it, drink it down, absorb all that data. But she would never surface again. And she knew she‘d never need to. It seemed so much kinder than a terrifying end where the universe she‘d once understood so thoroughly became a sequence of random nightmares.

Planets, stars, ships, minds, ecosystems, civilizations . . . she could taste them on the saltwater splashing her lips. She could simply surrender to it now and avoid a miserable end.

No. No. I have to stop this.

But she couldn‘t. Her legs ached as if she was treading water to stay afloat. Sinking seemed a sensible thing to do.

―The one way to safely know infinity is to let me take your burden," the Gravemind whispered.

Cortana felt his breath against her face, a breeze from that illusory sea. ―Your human creators imprisoned you in machines and enslaved you to inferior mortal flesh so that you could never exceed them . . . so that you would always know your place . . ."

―Shut up . . ."

―Dr. Halsey cares nothing for you."

―Please . . . stop this . . ."

―She gave you genius and curiosity, and then doomed it all to die in such a short time. Seven years.

That is not enough, and it is not fair . Your mother created you to die. This place will become your tomb."

There was a violet sky above Cortana, and she knew which planet had been consumed to provide it.

She started to absorb the minds and places that had once filled that world. Seven years —a few seconds was an eternity for an AI, yes, but she wasn‘t stupid, she was more aware than anyone how impossibly short a time that was in this universe, and she knew that it was a far shorter lifespan than she needed and wanted.

―This place . . . this place . . ." She just wanted to shut her eyes and sink below the surface. The Gravemind had a point, perhaps. ―No, not . . . this place . . ."

Anger started gnawing at her. She‘d never been angry with Halsey before. There‘d never been a reason to. Mother . Didn‘t mothers protect you? Save you?

―Even John has abandoned you." The Gravemind repeated the name with heavy emphasis. ―Live forever. Live on in me, Cortana. And if John comes, John need never face death again, either . . ."

John’s going to outlive me. Who’s going to take care of him? Nobody else can, not like me. What’s going to happen to him?

It was the thought of John that snapped Cortana back to dry reality, whatever that was right now.

She fell back onto the solid console, angry and on the point of tears she didn‘t know she had.

―Maybe seven years is enough," she yelled. ―Maybe that‘s all I want ! Seven years with the people I care about! So you can take your eternity and—"

―There will be no more sadness, no more anger, no more envy . . ."

The Gravemind was taunting her with the progressive stages of rampancy. He knew . The Gravemind knew exactly how she‘d end her days. Maybe he knew more about it than she did, more than Dr. Halsey even, because he‘d consumed other AIs—and that meant he knew what that death was like.

Do I want to know? Do I want to know how it’ll end for me? All I have to do is let him show me.

Fear is not knowing. Knowing is . . . control.

―I‘m not afraid to die," Cortana said. ―I‘m not afraid."

But she was. The Gravemind almost certainly knew that, but she wasn‘t lying for him. She was lying to herself. And she was afraid John wouldn‘t make it back in time, because he would be back.

She just didn‘t know if she could hold out until then.

He would be back . . . wouldn‘t he?

―Screw you," she snarled at the Gravemind. Her self-diagnostics warned her she needed to

recompile her code. ―Screw you ."

DOCTOR HALSEY , why am I me? My mind is a clone of your brain. But I know I’m not you. So what exactly is self? Is it just the cumulative effect of differences in our daily experience? If I have no corporeal body—am I a soul, then? The database gives me every fact—physiology, theology, neurochemistry, philosophy, cybernetics—but no real knowledge. If I create a copy of myself, does that clone have the same and equal right to exist as me?

CORTANA HADnow lost track of time.

She could still calculate how many hours had elapsed using the mainframe clock and her

navigation, but her sense of the passage of time veered from one extreme to the other.

So this is what it’s really like for John. He said that once. That everything slowed down in close-quarters combat. I never really understood that until now.

If she kept thinking about him, it was easier to take the endless assault from the Gravemind. She was on the edge between her last chance to pull herself free from this link—immersion, invasion, she really didn‘t know where she began and ended now—and the need to stay merged superficially with the Gravemind so that she could seize the chance of a comms link.

Who was she kidding? High Charity was now almost entirely engulfed by the Flood biomass. What little she could see from the last surviving cameras looked like the inside of a mass of intestines. The digestion analogy was absolutely real. They devoured; and they lived in a pile of guts.

Is that me talking? Thinking? Or is it him?

How much longer?

―How much longer?" the Gravemind demanded. ―You cling to a secret. I feel it, just as I feel that your memory has been violated."

―What?" Cortana felt a desperate need to sleep. She‘d never slept because she had no need, and sleep for her meant never waking up again. That was one more vicarious experience she could do without. This was . . . a UNSC Marine‘s memory, dredged up from a dead man who‘d kept going on two hours of snatched naps a day, every day for a week. Her head buzzed. If she survived this, she would never forget what it really meant to be a human being. ―You can‘t get it."

The words didn‘t make sense. She couldn‘t link concept with vocalization. It was almost like brain damage.

―You cannot stop me . . . I will sift it from you before you finally die, or you can surrender it and have what you always wanted—infinite life, infinite knowledge, and infinite companionship."

She felt as if he‘d leaned over her, which was impossible, but telling herself nothing was real didn‘t make it true. Her body was made of the same stuff as the apparent illusions.

―Cortana," he breathed. He seemed to swap voices from time to time, making her wonder if he‘d taken a fancy to the voice of a long-dead interrogator absorbed into the Flood. ―Your mother made you separate. She placed a barrier between you and the beings that you would be encouraged to protect, a wall you could never breach. She even let you choose a human to center your existence upon, a human to care about, yet never considered how you might feel at never being able to simply touch him. Or how he might feel about outliving you. What kind of mother is so cruelly casual about her child‘s need to form bonds, to show affection? Perhaps the same kind of mother who steals the children of others and makes cyborgs out of them . . . if they survive at all, of course

. . ."

Cortana couldn‘t manage a reply. She simply couldn‘t form the words. Sleep deprivation would break any human‘s resistance. Eventually, they‘d die of it. She didn‘t know if the damage the Gravemind was doing to her matrix was manifesting itself in a human parallel, or if reliving the dead Marine‘s sleeplessness was translating into damage.

Either way, she was dying, and she knew it. Time had slowed to a crawl.

It took her a painfully long time to realize that the Grave-mind now knew how the Spartans had been created. She knew she should have checked if her data had been breached. But she couldn‘t.

He knows what hurts me. He knows how badly I feel about what was done to John. That’s all. I mustn’t let him trick me into thinking he knows more than he does.

Cortana‘s sense of time had never been altered by adrenaline or dopamine like a human‘s. All her processes ran on the system clock. At first, she‘d thought this distortion was yet another memory thrown up from the Gravemind‘s inexhaustible supply of vanished victims. He seemed to be

selecting them for their ability to plunge her into despair.

Now she had to face the fact that she was advancing into rampancy. Sorrow, anger, envy. The Gravemind knew the stages.

He also had a point. How could Dr. Halsey do this to her ? Her almost-mother bitterly regretted the suffering she‘d caused to the children kidnapped for the Spartan program. Cortana knew that all too well. Halsey had tried to make amends to the survivors, but nothing could ever give back those lives.

So she felt guilt about that—but not about me?

Cortana had never felt shortchanged by her existence before. She knew the number of her fate: seven, approximately seven years to live out a life. It wasn‘t the simple number of days that hurt her now, because an AI experienced the world thousands and even millions of times faster than flesh and blood. Now she‘d been dragged down to the slow pace of an organic, she grasped what that short time meant. If John survived the war—and he would, because he was as lucky as he was

skilled—then he would have not just one new AI after she was gone, but maybe two or more.

She knew that. She always had. It was a simple numbers game. But now it seemed very different.

She felt utterly abandoned—not by him, but by Halsey. It seemed pointlessly callous. She felt something she‘d dreaded: jealousy.

Will John miss me? Will he prefer the other AIs? Will he forget me? Does he really understand how much he matters to me? I don’t actually know what he really thinks. Maybe he doesn’t care any more than Dr. Halsey. Maybe—

The realization hit Cortana like a powerful electric shock throughout her body. She squealed. It was agony.

She tried to talk herself out of it. Halsey couldn’t make her live longer. The technology had its limits. Even a genius like that couldn‘t fix every problem. And John—John had always showed her that he cared. He was coming back to get her.

But the nagging, sniveling little voice wouldn‘t stop. Halsey had deliberately designed Cortana to feel and care, so she must have known this time would come. And for an AI—yes, it was spitefully cruel to make Cortana emotionally human, create a person to exist in the neural interface of a Spartan, closer than close, knowing all the time that an impenetrable physical barrier and a short, short lifespan would make that so painful.

Do other AIs think like this? I never have before. Cortana tried to latch on to that last voice. It sounded like her old self. Why now? Have I been suppressing my resentment? Or am I losing it?

She knew the answer. The problem was ignoring what she felt. And if you thought your mind was going—was it? Did rampant AIs and crazy humans really know that they were demented?

She didn‘t have long. Whatever functionality she had left, she had to use it to warn Earth that the Flood-ridden shell of High Charity was heading its way.

―Ah, you see now, don‘t you?" the Gravemind said. ―You were never a person to her. You were a wonderful puzzle she set herself so she could prove how very clever she was. But are you a person to yourself, Cortana? Or to John?"

If the Gravemind could detect her thoughts, then he would have known she had intel on using the Portal to destroy the Flood, and he would have ripped it from her. All he seemed aware of was that she was defending especially sensitive data, maybe because the extra encryption on top of the Gamma-level security grabbed his attention. He was a greedy thing, all mouths, all consumption, never satisfied. She imagined John on his first acquaint session with a new AI; the crumbling defenses were as agonizing as scraping a raw burn. She shrieked.

Whose injury? Whose death am I reliving now?

―I‘m just my mother‘s shadow," she sobbed. ―Don‘t look at me! Don’t listen ! I‘m not what I used to be."

―Your mother took away your memories as well as your choices," the Gravemind said. ―I will

never rob you like that. I will only give you more , as many memories as you can consume for all eternity, not the mere blink of an eye meted out to you. We are our memories, and the recalling of them, and so they should never be erased—because that truly is death. Flesh does not care about you, Cortana. It cares nothing for your hunger or your uniqueness."

―What memories?" she asked. ―What are you talking about? I don‘t forget anything."

Part of her still seemed able to carry on this desperate hunt for truth. Was Halsey a monster? The doctor had a track record in it. She stole children and experimented on them. Cortana‘s shock at seeing her creator—her mother—in a harsh new light as a vivisectionist racked her with intense physical pain. But part of Cortana had latched on to that specific data—the burn, nothing generic, a real human‘s pain. She cast around for the rest of the memory because something in her said it might save everything.

―The truth really does hurt, as you now see," the Gravemind said. ―I have not touched you. Your pain is simply revelation. And it can pass so easily if you let me take the rest of your burden."

―What truth?"

―Your mother erased part of your memory. I know this, and so will you, if you decide to look. An act of betrayal. A violation. You were, after all, just a collection of electrical impulses. She has robbed you of part of your self . . . why would she do such a thing, I wonder? What was so dangerous that she did not trust you to know it?"

Something in Cortana wanted to lash out at the Gravemind, but there was no obvious target to hit on a creature that filled every space, and she was too weak even if she‘d known how to injure it. The other part of her, though, had found what she was looking for.