Cora continues to ramble on about the technicalities of time travel, including the possibility of running into our past selves and why we want to avoid that all costs. While she talks, I think about my brother. I wonder if it’s possible to stop him on that morning. That morning feels too late, but I can’t bring myself to say it.

I know Mrs. Martinez died because she approached Parker. Mrs. Martinez was the last person to die before Parker took his own life. My skin goose-bumps with fear. I don’t know if I can be as brave as Mrs. Martinez. Will I have the courage to stop Parker? To walk toward the thing I’m most afraid of instead of running away?

“Right,” I say. I shake my head a little and try to pay attention to Cora.

“Okay. Let’s not get distracted. It’s very important that we follow the steps of the scientific method.” Cora taps her finger against the notebook page for emphasis.

“The hypothesis,” I say. That seems like the least important part to me, but I don’t want to upset Cora.

“Right,” Cora says, and starts to talk at length about all the things that make a good hypothesis. I only register half of it. I’m still thinking about coming face-to-face with my brother. I don’t want to see the Parker from that morning. I want a Parker from earlier, the Parker he was before he changed—the Parker who held my hand in the ocean, the Parker who helped me get down from the tree, the Parker who taught me how to ride a bike. The Parker who used to sit with me on his bed, helping me sound out every word in my chapter book, patient when I got stuck on the s’s and th’s.

“Hey,” I say, interrupting Cora.

She gives me a slightly sour look.

“You know what you said earlier? About how we’re going to time-travel to stop Parker from hurting . . .” I stop talking for a moment and take a deep breath. “But he did something worse than hurt.”

“I know.” Cora’s voice is barely above a whisper. It’s so light that the fall wind blowing across the athletic fields almost swallows it up. “I just can’t say those other words. It’s too hard.”

I imagine the tiled floor of the science classroom. I’ve seen photos of it in the articles I read online. A cold sweat beads on the back of my neck. “This is all going to be hard. Really hard.”

“I know that.” Cora grits her teeth, and her eyes stick to mine like wet leaves on a windshield.

She doesn’t say anything else, but she doesn’t have to. We’re making a promise.

We’re going to do this together.

Seventeen

Cora

The truth is, I wasn’t so sure about the giant oak tree.

Quinn feels really strongly about it, though, and so I decided to roll with it. There’s no scientific consensus on where exactly the best place to find a wormhole is. Dad says what you’re looking for is scientific consensus. That means a group of scientists all agree on the same theory, which means the theory is probably right.