So Nathan put Aiko on a plane in San Francisco, and she arrived in Ithaca eight hours later (six hours after the tranquilizer wore off), foam-flecked and trembling. Stephen, who was running about a half an hour late, found her in the baggage-claim area, the crate haphazardly dumped into a corner so that in the echoing swirl of airport bustle, she could see only a scuffed wall. He turned the crate around with his foot and bent down to take a look. There was a heavyset yellow dog peering out with a look of desperate, studied blankness on her broad face.

She spent her days in Stephen’s backyard standing on top of the picnic table barking ceaselessly at the gray Ithaca sky or doing demolition work on his lawn, digging not holes but salad-bowl-size depressions every few feet and pulling down the trumpet vines that clung to the tall wooden fence. She would tug on them until they were stretched across the grass in long strands, their narrow purple flowers collapsing like wet crepe paper. Sometimes she napped in the poppy bed for an hour or so, sprawled on her back with her pale belly exposed, large dirty paws retracted against her chest, stout body framed by the delicate fronds smashed flat beneath her.

“We do not do that,” Stephen would tell her firmly, pointing to the ankle-turning holes, the trampled flower beds, the quarter-inch-deep toenail grooves in his back door. “Ever. Not.”

She whimpered in agreement and bolted in a fevered, dirt-churning circle, barking hoarsely into the evening air. As Stephen crouched to pet her, she raked her front paw across his face.

Since Nathan had stopped taking his calls, he complained instead to his mother. “My yard is now toast,” he said into her answering machine.

She picked up while he was still speaking.

“So what? You’re helping someone out for once,” she replied briskly. “What’s a yard? Is there anything more meaningless?”

This to her plant-biologist son, the one who worshipped moss. Next to his bed, right now, was a catalog listing nothing but varieties of fern. Every luminous green imaginable, every kind of intricate fringe.

“Thanks for understanding,” he said.

“Thank you, Stephen, for assisting your brother,” she replied pleasantly. “If Nathan can mend his situation, then he must do so; if not, he’ll move ahead.” She paused, pointedly, then went on. “Perhaps you’ll learn something by being involved with this about how to conduct a successful relationship.”

“Say what?” Stephen asked.

“You heard me,” she said. “And we’re not going to belabor it.”

His mother, Eleanor Klein, was an elderly and formidable pediatrician who still saw patients three days a week. She also managed Stephen’s father, an Alzheimer’d scientist who spent those same three days in his office at UC Berkeley, worrying the pens in his penholder and asking the secretaries staticky questions over speakerphone.