Alongside the other smokers, we got high in the alleyway for the first time in over a year. Erin told me about playing guitar in a dub-folk band and how she web-designed to pay the bills. I told her about the mouse experiments, and she didn’t make fun of me. Instead she said, “Are you kidding? That’s fucking incredible!” and looked at me with such curiosity that it was hard not to blush. I stared at the firebird tattoo on her neck instead; tattoos were something my timeline Erin hated. The bowl was cashed and she dug around in her pocket.

“Should’ve brought more,” she said. “We can puff at my place if you want. It’s in Chelsea, but I can give you a ride.”

No you can’t, I thought, looking at the garage across the street. “I have to finish an experiment tonight,” I said. “How about tomorrow? Want to go for a walk at the arb?”

“I free up at four.”

“Meet you by the gates?”

“It’s a date,” she said, and leaned forward, giving me a quick kiss, and the sudden softness of her mouth against mine was the most incredible feeling I’d had all year. I stood there, watching as she turned, thinking how there was a timeline where we were still in the alleyway making out, another where she was touring with a dub-folk band, and yet another where she’d soon leave the club and call the police about her missing car. Shit. I hurried back to the lab, highlighted her parallel self, and returned her to her own reality. Then I took out a pad and wrote down every detail I could remember: the sound of her voice, the warmth of her lips against mine, what it felt like to be wanted again. When I was done, I shut off the lights and went home to our apartment, where Erin was asleep, her own note on the kitchen table telling me to crash on the couch.

I hadn’t expected to fall in love again so quickly. But at work the next day I told Donnie I needed to go home early, and before leaving I isolated the alternate Erin, dragged her timeline over my own, and hit Enter. Six hours later, we were parked outside the empty lab, making out in my car while snow came down heavy against the steamed-up windows. I let her into the building, showed her the mice, and finally highlighted her timeline and dragged her back over hers. We kissed one last time, the whole universe feeling alive, then I hit Enter and there was just me, alone in the lab with the small lights of my computer blinking and our two mice sleeping tightly against each other.

So I did what I knew had to happen in this reality. I called Donnie.