“Gervais,” I said. “Not right now, okay?”

“Remember,” he said, ignoring this, “take your time on the first sets, even if they seem easy. You need them to prime your brain, lay the groundwork for the harder stuff.”

I nodded, not even bothering to respond this time.

“If you find yourself stumbling with the power rule, remember that acronym we talked about. And write it down on the test page, so you can have it right in front of you.”

“I need to go,” I said.

“And finally,” he said as, inside, my teacher Ms. Gooden was picking up a stack of papers, shuffling them as she prepared to hand them out, “if you get stuck, just clear your head. Envision an empty room, and let your mind examine it. In time, you will find the answer.”

He blurted out this last part, not very Zen at all, as he rushed to fit it in as the bell rang. Even in my distracted state, as I looked at him I realized I should be more grateful. Sure, we’d had a deal, and I had paid him his twenty bucks an hour when he invoiced me (which he did on a biweekly basis on preprinted letterhead, no joke). But showing up like this, for a last-minute primer? That was above the call of duty. Even for a multipronged, proven method like his.

“Thanks, Gervais,” I said.

“Don’t thank me,” he replied. “Just go get that ninety. I don’t want you messing up my success rate.”

I nodded, then turned to go into my classroom, sliding into my seat. When I looked back out the door, he was still standing there, peering in at me. Jake Bristol, who was sitting beside me looking sleepy, leaned across the aisle, poking my shoulder. “What’s up with you and Miller?” he asked. “You into jailbait or something?”

I just looked at him. Jerk. “No,” I said. “We’re friends.”

Now, Ms. Gooden came down the aisle, smiling at me as she slid a test, facedown, onto the desk in front of me. She was tall and pretty, with blonde hair she wore long, twisting it back with a pencil when she got busy filling up the board with theorems. “Good luck,” she said as I turned it over.

At first glance, I felt my heart sink, immediately overwhelmed. But then I remembered what Gervais had said, about taking my time and priming my brain, and picked up my pencil and began.

The first one was easy. The second, a little harder, but still manageable. It wasn’t until I got to the bottom of the front page that I realized that somehow, I was actually doing this. Carefully moving from one to the next, following Gervais’s advice, jotting the power rule down in the margin: The derivative of any given variable (x) to the exponent (n) is equal to product of the exponent and the variable to the (n-1) power. I could hear Olivia saying it in my head, just as I heard Gervais’s voice again and again, telling me the next step, and then the one following, each time I found myself hesitating.

There were ten minutes left on the clock when I reached the last problem, and this one did give me pause, more than any of the others. Staring down at it, I could feel myself starting to panic, the worry rising up slowly from my gut, and this time, no voices were coming, no prompting to be heard. I glanced around me at the people on either side still scribbling, at Ms. Gooden, who was flipping through Lucky magazine, and finally at the clock, which let me know I had five minutes left. Then I closed my eyes.

An empty room, Gervais had said, and at first I tried to picture white walls, a wood floor, a generic anywhere. But as my mind began to settle, something else came slowly into view: a door swinging open, revealing a room I recognized. It wasn’t one in the yellow house, though, or even Cora’s, but instead one with high glass windows opposite, a bedroom to the side with a dry-cleaned duvet, sofas that had hardly been used. A room empty not in definition, but in feeling. And finally, as my mind’s eye moved across all of these, I saw one last thing: a root-beer cap sitting square on a countertop, just where someone had left it to be found.

I opened my eyes, then looked back down at the one blank spot on my paper, the problem left unsolved. I still had three minutes as I quickly jotted down an answer, not thinking, just going on instinct. Then I brought my paper to the front of the room, handed it in, and pushed out the door onto the green, heading toward the parking lot. I could just barely hear the bell, distant and steady, as I drove away.

In a perfect world, I would have remembered not only where the apartment building was, what floor to take the elevator to, but also the exact number of the unit. Because this was my world, however, I found myself on the seventh floor, all those doors stretching out before me, and no idea where to begin. In the end, I walked halfway down the hallway and just started knocking.

If someone answered, I apologized. If they didn’t, I moved on. At the sixth door, though, something else happened. No one opened it, but I heard a noise just inside. On instinct—call it Zen mode—I reached down and tried the knob. No key necessary. It swung right open.

The room was just as I’d pictured it earlier. Sofas undisturbed, counter clutter-free, the bottle cap just where it had been. The only difference was a USWIM sweatshirt hanging over the back of one of the island stools. I picked it up, putting it to my face as I breathed in the smell of chlorine, of water. Of Nate. And then, with it still lingering, I looked outside and found him.

He was standing on the balcony, hands on the rail, his back to me, even though it was cold, so cold I could feel the air seeping through the glass as I came closer. I reached for the door handle to pull it open, then stopped halfway, suddenly nervous. How do you even begin to return to someone, much less convince them to do the same for you? I had no idea. More than ever, though, right then I had to believe the answer would just come to me. So I pulled the door open.