Fred's visor slowly depolarized.

Kelly leaned across her Banshee. Blood oozed from her ar- mor's left shoulder joint. She fumbled for her helmet seal, caught it, and peeled it off her head. "Did we get 'em?" she panted. Blood foamed from the corner of her mouth.

"I think so," Fred told her.

She looked around. "Joshua?"

Fred shook his head. "He got hit on the way in."

It had been easy for him to fly into the face of certain death moments ago. Saying those words was a hundred times harder.

Kelly slumped and dropped her head back against her Banshee.

"Stay here, I'm going up to take a look." Fred powered up his Banshee and rose parallel with the ridgeline. He nudged the craft up a little farther and got his first look into the valley.

It was a sea of flame. Hundreds of fires dotted the cracked, glassy ground. Where the Big Horn River had snaked along, there was now only a long steaming furrow. There was no trace of the cruiser or the Covenant troops that had filled the valley moments ago. All that remained was a field of smoldering, twisted bone and metal. At the edge of this carnage stood black- ened sticks—the remnants of the forest—all leaning away from the center of the explosion.

Ten thousand Covenant deaths. It wasn't worth losing Joshua or any of the other Spartans, but it was something. Perhaps they had bought enough time for the orbital MAC guns to tip the battle overhead in the Fleet's favor. Maybe their sacrifices would save Reach. That would be worth it.

He looked up into the sky. The steam made it difficult to see anything, but there was motion overhead: Faint shadows glided over the clouds.

Kelly's Banshee appeared alongside his, and their canards bumped.

The shadows overhead sharpened; three Covenant cruisers broke through the clouds and drifted toward the generator com- plex. Their plasma artillery flickered and glowed with energy.

Fred snapped open his COM channel and boosted the signal strength to its maximum. "Delta Team: Fall back. Fall back now!"

Static hissed over the channel, and several voices overlapped.

He heard one of his Spartans—he couldn't tell who—break through the static.

"Reactor complex seven has been compromised. We're falling back. Might be able to save number three." There was a pause as the speaker shouted orders to someone else: "Set off those charges now!"

Fred switched to FLEETCOM and broadcast: "Be advised, Pillar of Autumn, groundside reactors are being taken. Orbital guns at risk. Nothing we can do. Too many. We'll have to use the nukes. Be advised, orbital MAC guns will most likely be neu- tralized. Pillar of Autumn, do you read? Acknowledge."

More voices crowded the channel, and Fred thought he heard Admiral Whitcomb's voice, but whatever orders he issued were incomprehensible. Then there was only static, and then the COM went dead.

The cruisers fired salvos of plasma that burned the sky. Dis- tant explosions thumped, and Fred strained to see if there was any return fire—any sign that his Spartans were fighting or re- treating. Their only hope was movement; the enemy firepower would shred a fixed position.

"Fall back," he hissed. "Now, damn it."

Kelly tapped him on the shoulder and pointed up.

The clouds parted like a curtain drawn as a fireball a hundred meters across roared over their position. He saw the faint out- lines of dozens of Covenant battleships in low orbit.

"Plasma bombardment," Fred whispered.

He'd seen this before. They all had. When the Covenant con- quered a human world they fired their main plasma batteries at the planet—fired until its oceans boiled and nothing was left but a globe of broken glass.

"That's it," Kelly murmured. "We've lost. Reach is going to fall."

Fred watched as the plasma impacted upon the horizon and the sky turned white, then faded to black as millions of tons of ash and debris blotted out the sun.

"Maybe," Fred said. He gunned his Banshee. "Maybe not.

Come on, we're not done yet."

SECTION I

THRESHOLD

CHAPTER FIVE

1637 hours, September 22,2552 (Military Calendar) \ Aboard Longsword fighter, uncharted system, Halo debris field. Three weeks later.

The Master Chief settled into the pilot's seat of the Longsword attack craft. He didn't fit. The contoured seat had been engi- neered to mate with a standard-issue Navy flight suit, not the bulky MJOLNIR armor.

He scratched his scalp and breathed deeply. The air tasted odd— it lacked the metallic quality of his suit's air scrubbers. This was the first quiet moment he'd had to sit, think, and remember. First there was the satisfaction after the successful space op at Reach, which went sour after Linda was killed and the Covenant glassed the planet... and Red Team. Then the time spent in a Pillar of Autumn cryotube, the flight from Reach, and the discovery of Halo.

And the Flood.

He stared out from the front viewport and fought down his revulsion at the memory of the Flood outbreak. Whoever had constructed Halo had used it to contain the sentient, virulent xenoform that had nearly claimed them all. The rapidly healing wound in his neck, inflicted by a Flood Infection Form during the final battle on Halo's surface, still throbbed.

He wanted to forget it all. . . especially the Flood. Everything inside him ached.

The system's moon, Basis, was a silver-gray disk against the darkness of space, and beyond it was the muted purple of the gas giant Threshold. Between them lay a glistening expanse of debris—metal, stone, ice, and everything else that had once been Halo.

"Scan it again," the Master Chief told Cortana.

"Already completed," her disembodied voice replied. "There's nothing out there. I told you: just dust and echoes."

The Master Chief's hand curled into a fist, and for a moment he felt the urge to slam it into something. He relaxed, surprised at his frayed temper. He'd been exhausted in the past—and without a doubt the fight on Halo had been the most harrowing of his career—but he'd never been prone to such outbursts.

The struggle against the Flood must have gotten to him, more than he'd realized.

With effort he banished the Flood from his mind. Either there'd be time to deal with it later. . . or there wouldn't. Worrying about it now served no useful purpose.

"Scan the field again," he repeated.

Cortana's tiny holographic figure appeared on the projection pad mounted between the pilot's and system-ops seats. She crossed her arms over her chest, visibly irritated with the Master Chief's request.

"If you don't find something out there we can use," he told her, "we're dead. This ship has no Slipspace drive, and no cryo.

There's no way to get back and report. Power, fuel, air, food, water—we only have enough for a few hours.

"So," he concluded as patiently as he could manage. "Scan.

Again."

Cortana sighed explosively, and her hologram dissolved. The scanner panel activated, however, and mathematical symbols crowded the screen.

A moment later the scanner panel dimmed and Cortana said, "There's still nothing, Chief. All I'm picking up is a strong echo from the moon ... but there are no transponder signals, and no distress calls."

"You're not doing an active scan?"

Her tiny hologram appeared again, and this time static flashed across her figure. "There are trillions of objects out there. If you want I can start to scan and identify each individual piece. If we sit here and do nothing else, that would take eighteen days."

"What if someone's out there but they turned off their trans- ponder? What if they don't want to be found?"

"That's highly un—" Cortana froze for a split second. The static around her vanished, and she stared off into space. "Interesting."

"What?"

Cortana looked distracted, then seemed to snap out of it.

"New data. That signal echo's getting stronger."

"Meaning?"

"Meaning," she replied, "it's not an echo."

The scanner panel hummed back to life as Cortana activated the Longsword's long-range detection gear. "Uh-oh," she said, a moment later.

The Chief peered at the scan panel as Cortana identified the contact. The distinctive, bulbous silhouette of a Covenant cruiser edged into view as it moved around the moon's far side.

"Power down," he snapped. "Kill everything except passive scanners and minimal power to keep you online."

The Longsword darkened; Cortana's hologram flickered and faded as she killed power flow to the holosystem.

The cruiser moved into the debris field, prowling like a hungry shark. Another cruiser appeared, then another, and then three more.

"Status?" he whispered, his hands hovering over the weapons controls. "Have they spotted us?"

"They're using the same scanning frequencies as our system,"

Cortana said in his helmet speaker. "How strange. No mention of this phenomenon in any of the UNSC or ONI files on the Covenant. Why do you suppose they'd use the same frequencies?"

"Never mind that," the Chief said. "They're here and looking for something. Like I said before, if there are survivors out there, they'd be powered down."

"I can listen to their echoes," Cortana said, her voice flat and oddly procedural. Operating at lower power levels seemed to limit her more colorful behavior. "Process active: analyzing Covenant signals. Piggybacking their scans. Diverting more runtime to the task. I'm building a multiplex filtering algorithm.

Customizing the current shape-signature recognition software."

Another ship rounded the horizon of Basis. It was larger than any Covenant ship the Master Chief had seen. It had the sleek three-bulbed shape of one of their destroyers, but it must have been three kilometers long. Seven plasma turrets were mounted on universal joints—enough firepower to gut any ship in the UNSC fleet.

"Picking up encrypted transmissions from new contact,"

Cor-tana whispered. "Descrambling... lots of chatter... orders being given to the cruisers. It appears to be directing the Covenant fleet operations in the system."

"A flagship," the Chief murmured. "Interesting."

"Scan still in progress, Chief. Stand by."

John got out of the sysops seat. He had no intention of just "standing by" with seven Covenant warships in the system.

He drifted to the aft compartment of the Longsword fighter.

He'd assess what equipment was on board. He might get lucky and find a few of those Shiva nuclear-tipped missiles.

As he had seen when he first boarded the ship, the cryotube had been removed. He wasn't sure why, but maybe, like every- thing else on the Pillar of Autumn, the ship had been stripped down and upgraded for their original high-risk mission.

Where the cryo unit was supposed to be there was a new con- trol panel. The Chief examined it and discovered it was a Moray space-mine laying system. He didn't power it on. The Moray system could dispense up to three dozen free-floating mines.

The mines had tiny chemical-fuel drives that allowed them to keep a fixed position or move to track specific targets. These would come in handy.

He moved to the weapons locker and forced it open—it was empty.

The Chief checked his own assault rifle: fully functional, but only thirteen rounds remained in the magazine.

"Got something," Cortana said.

He returned to the sysops seat. "Show me."

On the smallest viewscreen, a silhouette appeared: a small, bullet-shaped cone with maneuvering thrusters on one end.

"It could be a cryotube," Cortana said. "Thruster and power packs can be affixed on their aft sections for emergencies... if a ship has to be abandoned, for example."

"And most of the crew on the Pillar of Autumn never had a chance to be revived from cryo," the Chief said. "They could have been jettisoned before the ship went down. Move us toward them. Docking thrusters only."

"Course plotted," Cortana said. "Thrusters engaged."

There was a slight acceleration.

"ETA twenty minutes, Chief. But given the Covenant cruis- ers' current search pattern, I estimate they will encounter the pod infive minutes."

"We need to move faster," the Chief told her, "but without firing the engines. The drive emissions will show up like a flare on their sensors."

"Hang on," Cortana said. "I'll get us there."

The Chief donned his helmet and locked its atmosphere seals.

Status lights pulsed green. "Ready," he said.

The aft hatch of the Longsword breached and slammed open.

There was an explosive sound as the atmosphere vented. The Longsword jumped forward; the Chief's head slammed into the back of his helmet.

"Adjusting course," Cortana said calmly. "ETA two minutes."

"How are we going to stop?" he asked.

She sighed. "Do I have to think of everything?" The aft hatch resealed, and John heard the faint hiss as the internal compart-ments pressurized.

One of the sleek Covenant cruisers slowed and turned toward them.

"Picking up increased scanning signal activity and strength,"

Cortana reported.

The Chief's hand hovered over the weapons system console.

It would take several seconds for the weapons to power up. The 110mm rotary cannons could fire immediately, but the missiles would have to wait for their target-lock software to initialize. By then the cruiser, which outgunned them a hundred to one, would turn the Longsword into molten slag.

"Attempting to jam their scanners," Cortana said. "That may buy us some time."

The Covenant cruiser turned away, slowed, and turned back to face the comparatively tiny Longsword. It took no further ac- tion . . . as if it were waiting for them to get closer.

So far so good. The Chief clenched and unclenched his gauntleted hand. We 're not dead yet.

He glanced at the scan display. The contact resolved into a clearer image: definitely a UNSC cryopod. It tumbled, and he saw that what he thought was a single pod was in fact three of them, affixed side by side.

Three possible survivors out of the Pillar of Autumn's total complement of hundreds. He wished there were more. He wished Captain Keyes were here. In the Chief's opinion Keyes had been the most brilliant spatial tactician he had ever encountered ...