I've never felt ugly next to Lena, but suddenly I do. I feel tall and ugly and bony, like a straw-colored horse.

Lena starts to say something when there's a loud knock on the door that opens into the store, and Jed calls out, "Lena? Are you in there?"

Instinctively I shove Alex sideways so he stumbles behind the door just as it begins to open from the other side. Fortunately, Jed manages to get it open only a few inches before the door collides with a large crate of applesauce. I wonder, fleetingly, whether Lena placed it there for that purpose.

Behind me, I can feel Alex: He is both very alert and very still, like an animal just before bolting. The door muffles the sound of Jed's voice. Lena keeps a smile on her face when she replies to him. I can't believe this is the same Lena who used to hyperventilate when she was asked to read in front of the class.

My stomach starts twisting, knotted up with conflicting admiration and resentment. All this time, I thought we were growing apart because I was leaving Lena behind. But really it was the reverse. She was learning to lie.

She was learning to love.

I can't stand to be so close to this boy, this Invalid, who is now Lena's secret. My skin is itching.

I pop my head around the door. "Hi, Jed," I say brightly. Lena gives me a grateful look. "I just came by to give Lena something. And we started gossiping."

"We have customers," Jed says dully, keeping his eyes locked on Lena.

"I'll be out in a second," she says. When Jed withdraws again with a grunt, closing the door, Alex lets out a long breath. Jed's interruption has restored tension to the room. I can feel it crawling along my skin, like heat.

Perhaps sensing the tension, Alex kneels down and begins unpacking his backpack. "I brought some things for your leg," he says quietly. He has brought medical supplies. When Lena rolls up one leg of her jeans to her knee, she reveals an ugly wound on the back of her calf. I feel a quick, swinging sense of vertigo and a surge of nausea.

"Damn, Lena," I say, trying to keep my voice light. I don't want to freak her out. "That dog got you good."

"She'll be fine," Alex says dismissively, as though I shouldn't worry about it--as though it's none of my concern. I have the sudden urge to kick him Ke tissively in the back of his head. He is kneeling in front of Lena, dabbing antibacterial cream on her leg. I'm mesmerized by the way his fingers move confidently along her skin, as though her body is his to treat and touch and tend to. She was mine before she was yours: The words are there, unexpectedly, surging from my throat to my tongue. I swallow them back.

"Maybe you should go to the hospital." I direct the words to Lena, but Alex jumps in.

"And tell them what? That she got hurt during a raid on an underground party?"

I know he's right, but that doesn't stop me from feeling an irrational swell of resentment. I don't like the way he's acting as though he's the only one who knows what's good for Lena. I don't like the way she's looking at him like she agrees.

"It doesn't hurt that bad." Lena's voice is gentle, mollifying, the voice of a parent soothing a stubborn child. Once again I have the sense that I am seeing her for the first time: She is like a figure behind a scrim, all silhouette and blur, and I barely recognize her. I can't stand to look at her anymore--Lena, a stranger--so I drop to my knees and practically elbow Alex out of the way.

"You're doing it wrong," I say. "Let me."

"Yes, ma'am." He shuffles out of the way without protest, but he stays crouched down, watching me work. I hope he won't notice that my hands are shaking.

Out of nowhere, Lena starts laughing. I'm so surprised, I almost drop the gauze right as I'm in the middle of tying it off. When I look up at Lena, she's laughing so hard, she has to double forward and put a hand over her mouth to try to muffle the sound. Alex watches her soundlessly for a minute--he's probably just as shocked as I am--and then he, too, lets out a snort of laughter. Soon they're both cracking up.

Then I start laughing too. The absurdity of the situation hits me all at once: I came here to apologize, to tell Lena she has been right to be cautious and keep safe, and instead I surprised her with a boy. No, even worse--an Invalid. After all this time and despite all her warnings, Lena is the one who has caught the deliria; Lena is the one with the biggest secrets--shy Lena, who has never even liked to stand up in front of the class, has been sneaking around and breaking every rule we have been taught. The laughter comes in spasms. I laugh until my stomach aches and tears are streaming down my cheeks. I laugh until I can't even tell if I'm laughing or whether I've started crying again.

What will I remember about the summer when it is over?

Twin feelings of pleasure and pain: oppressive heat, the frigid bite of the ocean, so cold it lodges in your ribs and takes your breath away; eating ice cream so fast a headache rises from the teeth to the eyeballs; endless, boring evenings with the Hargroves, stuffing myself with food better than any I have ever eaten in my life; and sitting with Lena and Alex at 37 Brooks in the Highlands, watching a beautiful sunset bleed out into the sky, knowing that we are one day closer to our cures.

Lena and Alex.

I have Lena back again, but she is changed, and it seems that every day she grows a little more different, a little more distant, as though I am watching her walk down a darkening hallway. Even when we are alone--which is rare now; Alex is almost always with us--there is a vagueness to her, as though she is floating through her life in the middle of a daydream. And when we are with Alex, I might as well not be there. They speak in a language of whispers and giggles and secrets; their words are like a fairy-tale tangle of thorns, which place a wall between us.

I am happy for her. I am.

And sometimes, just before going to sleep, when I am at my most vulnerable, I am jealous.

What else will I remember, if I remember anything at all?

The first time Fred Hargrove kisses my cheek, his lips are dry on my skin.

Racing with Lena to the buoys at Back Cove; the way she smiled when she confessed she'd done the same thing with Alex; and discovering when we got back to the beach that my soda had turned warm, syrupy, undrinkable.

Seeing Angelica, post-cure, helping her mother clip roses in their front yard; the way she smiled and waved cheerfully, her eyes unfocused, as though they were fixated on some imaginary spot above my head.

Not seeing Steve Hilt at all.

And rumors, persistent rumors: of Invalids, of resistance, of the growth of the disease, spreading its blackness among us. Every day, streets papered with more and more flyers. Reward, reward, reward.

Reward for information.

If you see something, say something.

A paper town, a paper world: paper rustling in the wind, whispering to me, hissing out a message of poison and jealousy.

If you know something, do something.

I'm sorry, Lena.