I had known Nate Calloway for three weeks, and tonight I was holding his arm in the lobby of a Chicago hotel ballroom as though I had been doing it for years.

The arrangement was simple. Preston Hale, who had ended our two years by text message eight months ago, would be at this charity gala with his new fiancée, and I had been invited by a client who did not know any better. I could not afford the ticket. I could not afford the dress either, but it was green and it fit, and I told myself that was enough.

Nate rented the studio above my bakery. He was an architect with ink on his cuffs and a habit of leaving his door open, and he had found me one night on the back stairwell, on the phone with my sister, saying Preston's name like something I had swallowed wrong. He had waited until I hung up. Then he had said, mildly, "I own a tux and no dignity. If you need someone to stand next to you, I'm available."

I laughed. Then I thought about it for four days and said yes.

We made the rules in the elevator on the way up. Hand at the waist, nothing lower. Nothing more than a cheek or a temple. No kissing unless Preston was looking right at us, and even then only if I gave a sign. I would tug my earring. Nate agreed to all of it very seriously, and I noticed he did not look at me while he did.

The ballroom was all chandeliers and low gold light. A string quartet played something I half recognized. Nate wore black tie like he had been born in it, and when his hand settled at my waist, warm and careful, I felt it the way you feel a stove you have been told is off.

"Breathe," he said quietly.

"I am breathing."

"You're doing it like a person being chased."

I breathed properly. He smiled, just slightly, and steered me toward the bar.

For the first hour, we were fine. Better than fine. A woman in pearls asked how long we had been together, and Nate said, "Seven months," without hesitation, and then told her we had met in a rainstorm over a stolen umbrella. He made up the whole thing as he went, the bus shelter, the croissant I had supposedly shared with him because I felt sorry for a soaked stranger. I was a pastry chef. It was exactly the kind of thing I would have done.

"You're good at this," I whispered when she left.

"I pay attention," he said, and that was all, and he turned to hand me a glass of water as though it were nothing.

It was not nothing. I noticed that he had remembered I did not like champagne. I noticed that he never once glanced across the room to find Preston, but stayed turned toward me, so that anyone watching would see a man who had eyes for only one person. It was a good performance. I kept reminding myself of that.

At nine, Preston found us.

He came across the floor with his fiancée on his arm, her laugh bright and brittle, and stopped just close enough to be rude. "Claire. I didn't think you'd come."

"I was invited," I said. My voice sounded thin.

His eyes moved to Nate. "And you are?"

"Nate." He did not offer a hand. His arm slid around my waist, gentle but unmistakable. "I'm with Claire."

Preston made a remark about how quickly I had moved on, and his fiancée giggled into her glass, and the old humiliation came up hot in my throat. I felt my hand drift toward my earring. It would have been easy. One tug, one kiss, and Preston would walk away thinking he had lost something.

Nate felt it. His fingers tightened very slightly at my waist, not a command, just a question. I looked at him. He gave the smallest shake of his head.

"You don't have to," he murmured, so low that only I heard. "Not for him."

My hand dropped. I turned back to Preston and said, quite calmly, "It was nice to see you," and I let Nate walk me away. Behind us, Preston said nothing. It was the strangest victory I had ever won.

We ended up near the tall windows at the edge of the dance floor, where the glass held the city in black and silver. My heart was still pounding, and not from Preston. I leaned on the sill and let out a breath.

"Thank you," I said. "You didn't have to do that. The rules said I could have."

"The rules were for him." Nate looked out at the skyline instead of at me. "I didn't like the idea of you using the signal and then regretting it."

"Maybe I wouldn't have regretted it."

"Maybe not." A pause. "I would have."

The words hung between us, quiet and surprising. I turned my head. His profile was lit by the chandeliers behind us, sharp and tired and gentle all at once, and I realized with a slow, sinking certainty that I was standing very close to him and had not noticed myself moving.

The quartet slid into a waltz. Couples drifted past us toward the floor.

"We should dance," I said. "Someone might be watching."

"Nobody's watching."

"Then why would we dance?"

He finally looked at me. Whatever he saw made him go still, and for a moment neither of us was playing anyone. "Because you want to," he said carefully. "And so do I. That's not in the rules, I know."

I put my hand in his.

It was not a dramatic dance. We kept a polite distance, the one the napkin would have approved of, his palm flat against my back, mine resting on his shoulder. But I could feel the steadiness of his breath, and the slight tremor in his fingers, and I understood that he was trying very hard not to hold me closer. I understood it because I was trying too.

"Claire," he said, near my ear. "There's something I should tell you. About why I offered to do this. I've been meaning to since the elevator."

My pulse stumbled. "Tell me."

He drew a breath, and I felt it against my temple, and the whole room seemed to lean in with us. "The truth is, I've known who you were long before the stairwell. I..."

And every light in the ballroom went out.