“Let’s do it,” Jules said, action-hero serious, then took off down the block the wrong way, Sam following at a slower trot.

“Um.”

“Riverside!” Jules shouted back. “Mixing it up!”

It took the crosswalk light for me to catch them, and the effort of launching myself into a sprint nearly did me in. My head throbbed—lack of sleep doing me no favors—and my legs felt rusty and sore, underused and overtaxed at the same time.

My body hurt. It was the best distraction I could have asked for.

By the time we passed the Seventy-second Street dog run and continued under the thundering parkway, lights danced at the corners of my vision—but I pushed on. If I stopped, my brain would restart, repeating the events of last night, including how it had ended. Not only that, but if I wasn’t running, I’d have to return home, risking an encounter. So I outpaced Sam and chased Jules’s ponytail up the wide concrete path, dazzled by the light reflecting off the Hudson.

This park always felt like the edge of a snow globe to me, like if I tried to swim out, I would hit a glass wall and have to come back. I’d left the city plenty, of course, traveling with Dad or Mom to events, from Teatro Colón to Royal Albert Hall to the Sydney Opera House, or down south to see the grandfolks, but never by myself. Alone, I felt bound to this island. I tracked the edge of the imagined glass as I ran.

By the time we got to the boat basin, my lungs had started to sting so much, the pain went white and vanished. Was this runner’s high? It felt more like runner’s anesthesia.

“Hey!”

I glanced back to see Jules stopping beside a bench. How had I gotten ahead of her? The second I slowed, my knees decomposed into jelly. I walked back to her like a drunk person pretending to be sober.

“Look at you,” she called out, palms clamped against her legs while she caught her breath. “Don’t injure yourself.”

“I won’t.” I fell sitting beside her. “I think . . . I’m done for today.”

“Good. I only run like that when I’m pissed off. And then I don’t know when to say when.” She pulled her hair from its ponytail, mussed it peevishly, put it back in. Then she turned to me. “So?”

“So . . . what?” I winced. My lungs were stinging again.

“What are you pissed about? Did something happen last night, besides what half the city got to witness?”

I wiped my face, annoyed that she was bringing it up—even more annoyed that I’d given her a reason to. “I don’t know what that was. I think it’s already over.”

“You do move fast.”