When she asked him a question that revealed some chasm in her learning, some gap where a concept should have existed, he put his head in his hands as if trying to summon the energy to explain all that would need to be explained to her to make her fully formed. But he didn’t despair: he started from a point that was more rudimentary than he thought necessary (generally it was, in fact, necessary) and proceeded from there, his graceful geometrical hands drawing diagrams on the pads of paper that he collected from conferences and hotels and then hoarded in his desk. He often said he could not speak without a pen in his hand. He waved with his pen, pointed with it, scribbled absentmindedly when on a telephone call. He drew funny things like flowers and birds when he was talking to Ada, and sometimes during her lessons. For the rest of her life, Ada did this, too. She adopted many of David’s habits. They were alike: everyone said it. And that he understood her—more than anyone else in the world ever understood her—seemed to her like an incredible stroke of luck. “You are more machine than human, Ada,” he said at times. And it was the truth, not an insult. And it was calming to her to be so understood. And, sometimes, she felt it was why he loved her.
She thought of this image as she tried to fall asleep. She pictured herself with David at his desk, the two of them bowing their heads together, their minds a Venn diagram—Ada’s mind full of childish trivia, and David’s full of the mysteries of the universe, and the center between them growing, growing. In these moments he was Zeus to her, and she Athena, springing fully formed from the head of her father, alight with grace and wisdom. There they were at the lab or at home, the two of them, always the two. There they were solving whatever problem it was that she was facing.
In the morning, Ada was woken from a dream about David by the sound of the bedroom door creaking slowly open. There in the doorway stood Matty, holding a canvas tote bag and observing her. She sat up in bed and rubbed her hands over her face.
“I just have to get some stuff out of here,” said Matty, and then he came in and gathered up all of his Lego people and parts, two books, a small portable radio with a trailing wire. All of this he stuffed into his canvas bag, looking sideways at her as he did.
He sidled toward her before he left the room. He said to Ada, “Where’s your dad?”
She lifted her shoulders and lowered them slowly. She kept her face very still.
Then he turned on his heel and closed the door firmly behind him. Ada heard him running down first one and then another flight of stairs, into the basement, she assumed.
Ada rose and tiptoed to the door and put her head out into the hallway. It was a Sunday, and everyone else seemed to be asleep still. As quietly as she could, she descended the stairs and went into the kitchen, where Liston’s work was sprawled out over the table, and a yellow phone was mounted to the wall. She lifted the receiver from its cradle and dialed the number for her and David’s house, holding her breath while the rings came, four in a row, five, ten. Nobody answered.
Then, hanging up the telephone, she pondered her options. It still felt odd to be in Liston’s house for almost the first time after so many years of knowing her. She had no idea about Liston’s habits or her daily routines—no idea, for example, whether she was an early riser on weekends or preferred to sleep late, and no idea what she did when she was not at work and not with David. If Ada had been at home with David, she would have known what to expect from her weekend: David would have stayed in his home office for most of the day, breaking for every meal; Ada would have read or worked on the assignments that David gave her. Some weekends they did something different and interesting: a trip to a nearby mountain for skiing in the winter, for example; or, in the summer, a trip to a cabin in upstate New York that David had been renting since the fifties; or some other excursion to a nearby town or city. Sometimes they went to Washington, D.C.; David had a friend there named George, an artist, one of the few people he had kept in touch with from his childhood. He also went on several work trips a year, to conferences in locations as mundane as Cleveland and as far-flung as Hong Kong. These counted as their vacations: typically they would stay a few extra days in every place, seeing more than they otherwise would have. Sometimes, if he’d be in meetings all day and he thought that Ada would have nothing to do, he went by himself to conferences; on these occasions, he paid the division secretary, Martha, to stay with Ada at the house on Shawmut Way, and returned as quickly as he could. And there were, of course, the yearly trips to New York City, always in winter, always to see the Christmas concert at Calvary Episcopal. On those same trips, they would see an opera or a ballet at Lincoln Center, and visit the Met, and walk in Central Park. David always reserved the same accommodations: two adjacent rooms on the third floor of a bed-and-breakfast in Brooklyn Heights (“Manhattan is overpriced,” he always said, though Ada secretly wondered if he wished to limit, as much as possible, his chances of running into acquaintances from his past), owned by a charming, fragile septuagenarian named Nan Rockwell. She served scones for breakfast and talked with David about classical music until late into the night, playing on her turntable famous recordings that she sought out and traded for like cards. Always, they had dinner at a little cafeteria near Union Square, a nondescript place that David said reminded him of his youth, for reasons he did not explain to Ada.
Ada did not think Liston had any interest in doing these things. She came on most of the work-related trips that Ada and David took, but kept to herself, proclaiming her hatred for hotel rooms and her love of home. In her tastes she was polite but not adventuresome; she hopefully scanned every English-language menu they were presented for its blandest, palest dish. Until yesterday, Ada had always imagined that she did cozy things on weekends, made popcorn, watched movies with her boys, cooked meals with her oldest, Joanie, when she stopped by with the baby. How Ada came up with this idea, she was not certain: she had no reason to believe that the scientifically inclined Liston was domestic in any way. She knew that Liston did not like to cook, and could not abide housework. (She bragged often about raising her boys to be good husbands, assigning the weekly chores on a magnetic whiteboard that she stuck to the refrigerator.) Despite this, she still seemed traditional to Ada, in a way that Ada and David were not, and in a way—if she was honest with herself—that she envied. Liston drank Diet Coke. She brought ham-and-cheese sandwiches to work, on white bread. The sight of them made Ada’s mouth water. The idea of Liston’s house as a bastion of normalcy and tradition, right down the street, was one that Ada had always kept dear: it seemed somehow to anchor her and David’s house physically, in the same way that Liston’s friendship with them proved reassuringly to Ada that there was nothing so unusual about her situation, after all.
It was not until shortly after nine that Ada noticed any movement upstairs. Upon hearing it, she tiptoed to the downstairs bathroom to hide, in case it was one of the boys. She did not want to greet them before their mother was there to protect her.
Ada heard footsteps walking down the stairs and into the kitchen, just as she had done, and then someone picked up the telephone receiver. She could hear it all quite clearly.
“It’s Di,” said Liston, in the other room.
Ada didn’t know whom she had called, but she began to describe to the person the events of the day and night before, beginning with Ada’s phone call to her. Ada froze. She thought perhaps she should clear her throat or turn on the water to let Liston know she was there, but she was immobilized by shyness and fear. She stood still, clutching herself around the middle.
“She’s still at my house. She’s upstairs sleeping,” said Liston.
She paused.