“We should go,” he says as he gets to his feet.

“Okay.”

We start walking again. I still don’t know where we’re going. There doesn’t seem to be a path, but Ty acts like he knows the way. He keeps looking over his shoulder, behind us, like he’s afraid, and this makes me afraid. It’s suddenly so dark. The shadows are coming at us from every direction.

We walk faster. I’m out of breath. I stumble on a tree root or something.

I fall.

Ty grabs my hand and helps me to my feet. In the woods behind us there are more snapping branches and crunching leaves, the sounds of something moving toward us. Something stalking us. Something big.

I’ve hurt my ankle. Bad.

“It’s a bear,” Ty says, when I open my mouth to tell him that I’m not going to be able to run. “A grizzly.”

“There aren’t grizzlies in Nebraska.”

“We should climb that tree.” Ty picks a huge, spreading oak, which also shouldn’t be in these woods. “Can you climb it?”

I don’t have any experience climbing trees, but I try. I scramble up the trunk, ignoring the pain in my ankle, reaching at branches. Ty follows behind me, helping me balance, pushing me up, coaching me. But I’m slow. I don’t climb high enough or fast enough. I’m clumsy.

“Hurry!” Ty cries. “It’s here.” It’s so dark I can hardly see, but I can make out the huge silver-tipped shoulders of the bear below us, impossibly big. It makes a kind of chuffing noise, like a bark. It stretches up toward us. Then it has Ty’s foot in its mouth. It starts to pull him out of the tree.

I grab his arms. I hold on.

Ty looks into my eyes. He smiles, and it’s a sad smile, because he knows how this is going to end. We both do.

He says, “Don’t watch. Stay up here, where it’s safe. It will be over soon.”

“Ty, no.” I clutch his arms tighter. “Don’t.”

The bear is too strong. I can’t hold him. He’s yanked away. He falls. In the blackness of the forest, I hear him scream.

This is a dream, I tell myself. This is only a dream. He can’t die again.

But he does. I hear the bear kill him. There are roars, Ty’s yells of pain and terror, the ripping of fabric and the cracking of bones. I press my face into the rough bark of the oak tree, and I squeeze my eyes closed, and I listen to him die. Even then, in my dreams, I can’t cry for him. I can’t stop it. I can’t help.

I am completely useless, I think. I can’t save him.

Then, when it’s over, when the woods fall silent again, I wake up. In my own room. In the dark. Alone again.

I’ve been having these dreams for weeks now. They’re always the same, me and Ty, doing something we used to do, talking the way we used to talk, and then, after a while, something goes wrong and Ty dies. So far he’s died in a plane crash and gotten shot by a gang member and been struck by lightning during a thunderstorm. In one he fell down a set of stairs and broke his neck. In another he got hit by a car while we were riding our bikes to school. It’s like my own personal version of Kenny from South Park, except that Ty never dies the way he actually died. And every time he dies, every time I watch him, it feels real.

My stomach churns like I might vomit. I take a few deep, steadying breaths, like when Dad was in his Pilates phase and made us all learn to breathe from our core, and I sit up. I push my tangled hair out of my face. And then my heart lodges itself in my throat like a chunk of ice.

In the dim light from my bedroom window, I see a figure standing there. A silhouette. A person.

“Ty?” I croak.

The figure shifts slightly, as if he’s been looking out at the street but now he’s turning around. He doesn’t speak. I fumble for my glasses on the nightstand. I’m bat blind without my glasses. When I was a kid I used to freak myself out in the middle of the night, thinking that if a monster came out of my closet to get me, I wouldn’t see it until it was too late.

My fingers close around the frames. I unfold them carefully, bring them to my face, and look again at the window.

He’s not there. There’s just the shadow from the weeping willow tree outside.

I fall back on my pillow.

A shadow. A stupid shadow. From the stupid tree.

Ty’s not ever going to be here when I open my eyes, I tell myself sternly. Not for real. No matter what I dream about.

I turn onto my side, my face to the wall. I will myself to go back to sleep. I go with the tried and true method: numbers. 0, 1, 1, 2, 3, 5, 8, 13, 21, each number the sum of the two numbers before it. The Fibonacci sequence, it’s called, after an Italian mathematician who wrote about it in 1202. Fibonacci numbers are everywhere, in nature, even, in the pattern of leaves on a stem or the way the circles present themselves on the skin of a pineapple or the arrangement of seeds in a pinecone. Math. Safe, reliable math.

There is nothing more real than numbers.

My heartbeat starts to slow. My shoulders relax. I let myself breathe.

34. 55. 89. 144.

I remember that I’m wearing my glasses, and I take them off, fold them, and reach behind me to set them on the nightstand. The room goes dark and blurry, like an impressionist painting, colors but no distinct lines. Like a Van Gogh painting, I used to tell myself. Starry Freaking Night. I pull the covers up to my chin.

233. 377. 610. 987. 1,597. 2,584.

And it’s right then, as my eyelids begin to get heavy, as I start to drift off to the gray space where Ty isn’t dead, that I smell it.