Knock, Knock

It was just for the summer. And when he came back from Berkeley at the end of August, he would bring her a sea horse from the biology lab, which was next door to the physics lab where he would be smashing and separating and studying atoms in a way that really couldn’t be explained very simply—he shook his head—without also explaining some of the more basic principles of particle physics in specific and mass spectroscopy in general.

Her father closed his eyes for a second, slumping back against the Pontiac’s green vinyl seat. But the sea horse, he said, giving the dashboard a decisive slap, the sea horse would be a beauty, not like that sad crust of a thing glued to the specimen board at the Boise Science Museum, but a real—live—marine—creature sailing up and down on its uncurling tail in a case of perfect seawater blue. On his first trip down to Berkeley, he had seen a whole aquarium full of them, bobbing daintily as ballerinas. They were a fish, actually, he said, but most people didn’t know that. Most people thought they were crustaceans because of their bony-plated skin and prehensile tails.

Rennie stood next to the car and peered in at her father through the Pontiac’s open window. He seemed to be examining their house in his rearview mirror. He cleared his throat. It had been amazing to him to discover lately that some people seemed to be laboring under the misconception that feelings and hunches were as accurate an indicator of truth as empirical data. Which was obviously, ha ha, just not good science. He flinched as somewhere inside the house a window slammed shut. But, he said, coughing a little, no matter what anyone else said, no matter what crazy ideas some people had in their heads, he would definitely be back in Boise by the end of August. Even before she started school. Third grade, with Mrs. Culbertson, right? See, he hadn’t forgotten. He ran his hand back and forth around the top half-moon of the steering wheel. Early September, at the very latest. The very—he promised. He looked down at her and then sighed. “Renata,” he said.

She was hanging on to the Pontiac’s door handle, carefully examining its lock button and pushing it in and out, in and out, in and out.

“Renata,” he said again. “That’s enough.” He tried to gently remove her fingers from the door’s handle. In the end, he was forced to swat at her quite hard before he could pull out of the driveway, roll down the block past the Dornans’ forsythia bushes, and glide around the long corner toward the highway and beyond.

Now there was a lot of vacuuming and mopping and bathroom-tile scrubbing with “The Girl from Ipanema” and “King of the Road” playing at full volume. Their mother would hold a broom in one hand, hitch Double up high on her hip with the other, and sweep back and forth across the green-speckled linoleum of the kitchen. “Who’s my baby—Walter Walter-son—who’s my little bunny?” she’d say, dipping her hip dramatically toward the floor to make Double scream. “Who?” she’d demand.

“Who?” he would echo, clutching stickily at her shirtfront.

Double was much too small for his age, which was five and a half. He was also, the doctors said, a little slow. He had been born two months too early, in January instead of March, and had “suffered an amount of perinatal hypoxia sufficient to affect the periventricular white matter located deep inside the brain.” Rennie had seen the papers that her father kept buried under his physics teaching files. She had creased and uncreased the papers until she could say the words in her head, and even sometimes out loud. “Perinatal hypoxia,” she would whisper as she sat on the...