“As opposed to this one.”

She found she could not make herself say Ovid’s name. “Is he worried?” she asked finally. “Is this really terrible for the butterflies?”

“It could be worse.” Pete seemed to be making a point of showing no emotion. “It was definitely low twenties last night, so the microclimate of these firs is protecting them up to a point. Like they do in Mexico. I guess he wants a temperature profile of the roost through this cold stretch to see what they can actually survive.”

“Where did he go?” she asked.

“He had the camera. I think he’s doing a photo census.”

She remembered a detail Pete had forgotten: to record the serial number of each button before sending it up the tree. He did seem a bit rattled, so maybe things were worse than he was willing to say. She asked about the plan for the pillowcases.

“Oh, right,” Pete said. “Those can’t lie around up here all day, somebody needs to take them down to the lab this afternoon. What you do,” he said, giving her to know who somebody would be, “is you shake the butterflies to the bottom and pin the pillowcases up on a clothesline or something. Open-side up. You can rig up a line in the lab. And then you just watch them.”

“You watch pillowcases full of dead butterflies?”

“They’re not all dead. There’s a bunch of sleepers in there, you’ll see. When they warm up they start crawling up the inside of the pillowcase. At the end of the day you count the living and the dead, and do the math. You get a proportion. Multiply that figure times all the bodies we counted on the ground, and that’s your mortality estimate.”

She thought this through, stepwise. “Could I hang them up in my house?”

“Sure. It’s probably warmer than the lab,” he said, which was true, but she was thinking of Preston when he came home from school. He would sit on the edge of a chair and watch those pillowcases for all he was worth. He’d race to tell her each time another sleeper struggled from its stupor to begin the slow climb, pressed between soft walls of fabric. She and Preston would cheer for the stragglers, because at the end of the day, it was something they could do. Count the living and the dead, and do the math.

Dellarobia forgot about eating her lunch until well past noon. Pete had left her rigging up more lines for buttons while he shot more arrows. Sometimes he crouched on his heels at the plywood table and entered sequences of mystery data into Ovid’s small computer. Ovid himself remained at large. The sun gained its legs in the forest throughout the morning, warming the air by imperceptible degrees until she realized her fingers had thawed and she no longer needed some of her outer layers. Around the time she shed her coat the temperature touched some threshold that set off an extravagant spectacle of butterflies twitching open and even launching. The air got crowded with little celebratory bursts of action, like rice at a wedding. She stopped tying fishing line through bracelets of pipe and lifted her gaze. Pete looked up from his keyboard, the boys stopped counting bodies and rose unsteadily from the ground like soggy-kneed zombies. As a congregation they lifted their eyes in thanks. There was no whooping or backslapping, as when Pete’s arrow bested the tree. The difference was understood.

She felt lightheaded, then, and remembered hunger in its full measure. She grabbed her shoulder bag and headed for the big mossy log that was still the study site’s best furniture. Carlos and Roger were there, black knees and all, their coats flung on the ground, shirtsleeves rolled to the elbows, standing on the log bridge with their crossed arms in front of their chests, playing some game of trying to bump one another off. Carlos was the taller, with gingery hair, despite the Mexican-sounding name. Roger’s two-week beard and perpetual baggy shorts made her think of Snow White’s dwarves.

“Hey, Dellarobia,” they both called as she approached. They seemed to relish pronouncing her name, in a manner she’d seldom experienced. Maybe in California people took the unconventional in stride. Automatically she assessed the distance the boys could fall, maybe a sprained ankle’s worth, and the cellophane skins of their former lunches spread over the log. A mother, regardless of job title. She resisted the urge to clean up and seated herself a safe distance from their roughhousing. The peanut butter sandwich in her purse had burrowed to the bottom, and she had to unload a pile of things to unearth it, setting them beside her on the log: four disposable diapers, socks, a box of Bug’s Life Band-Aids, and an ice-cube tray for which she had no good explanation.

Ovid Byron materialized and took a seat on the other side of her little pile. Her face flooded scarlet as she hastily squirreled away the weird collection and unwrapped her sandwich. “Morning,” he said cheerfully, heedless of the exact time, or her trauma. He seemed to have no special feeling about seeing her. “How are you holding up?”

“Fine.” The answer, then, was no, he wasn’t aware. Heaven help her. She could stay on this log and in this world. She studied her PBJ, the strata of brown and florid purple between white cushions of bread. Or maybe he knew, and didn’t mind. Was that possible? He must have seen that image of her on the Internet, essentially naked, and had certainly never mentioned it. Cautiously she glanced at his sandwich, something bulbous and store-wrapped, probably picked up by Pete in town. Ovid’s enthusiasm suggested it was the first food he’d seen on a long, cold day. He had been up here since dawn.

“Have you got enough to eat there?” she could not help asking.

“It will have to be,” he said. She risked a glance at his face, and he disarmed her with a look of frank gratitude that made her falter. For what? She had nothing to offer. She’d been so flustered this morning, she hadn’t even brought a thermos of coffee.

“You know what I could do,” she said, winging it utterly. “I could make a pot of soup this afternoon and bring it up here to feed everybody. Pete wants me to take those pillowcases of butterflies to the lab. If you all mean to be up here till dark, you’ll need more than a sandwich to go on.”

“It’s so funny you mention that. I was just thinking of my wife’s noodle soup.”

This, she found, was not what she wanted to hear. “Is she a good cook?”

He smiled, rubbing his chin with the back of his hand. “She is a terrible cook.”

Dellarobia was unconscionably cheered by this news. “Well, I make a pretty decent chicken noodle soup. I could probably get it up here in a couple of hours.”