“Those aren’t nature,” he said. “They’re supernatural.”

She hummed a little in thought. “Do you believe in the supernatural?”

“I think I’d be irresponsible not to,” he said. “I’m sure there are explanations. I just don’t have time to consider them.”

“True. Not with time travel to puzzle out.”

“Right,” he agreed. “Only one impossibility at a time.”

Regan was silent for a moment. He didn’t feel the need to fill it. Instead, Aldo leaned his head back and lingered in the quiet contemplation that swung between them.

“Rainbows,” she said.

“What about rainbows?”

“They could be circles,” she said. “That arc is, you know. Circular, right?”

“Could be. But symmetry is only implied, and symmetry doesn’t often happen in nature, either.”

“True,” she sighed. “We did some facial compositions with symmetry in one of my drawing classes and they were terrible. Disturbing, even.”

“Yes,” he agreed, glancing at the still-dark sky outside. “Why are you whispering, by the way?”

“My boyfriend is sleeping.”

“Ah,” he said. “And you just figured I’d be awake, or did you plan to wake me?”

“I wasn’t really thinking about you, to be honest.”

For whatever reason, he smiled.

“Anything else going on in your mind?” he asked her.

Evidently yes. “Why hexagons?”

“Patterns, mostly,” he said. “Kept running into them, especially in math. They’re the basis for quantum groups.”

“And they occur in nature?”

“Yes. William Kirby called bees ‘heaven-instructed mathematicians.’”

“But that’s wrong,” Regan said, sounding distressed. “Bees are godless.”

Aldo cupped his hand around a low laugh. “Well, Darwin conducted experiments to prove that it was instinct related to evolution.”

“Oh, good.” She sounded relieved. “Better.”

Aldo reached over, turning on the lamp beside his bed. Clearly he wasn’t going to be doing any more sleeping. “What did you do tonight? Or last night, I guess.”

“Nothing. Nothing interesting. You haven’t been to the museum lately,” she added as an afterthought.

He hadn’t wanted to overwhelm her. It was feeling less and less like an accident that he was associating the two of them in his mind.

“It’s one place I go,” he said, “but not the only one.”

“Where else?”

“Outside, if I can. That’s ideal.”