She wakes on Saturday to a crunch of pain in the center of her back and a hammer in her skull. Her clothes are wet with sweat and stink. She kicked off her shoes in the night, and her sweater as well, but her blouse sticks to her stomach and her socks are so damp that when she peels them off they drop heavily to the floor of the car. She sits up in the backseat. Outside, it is morning, and Grant Street is thick with rain.

She brings the heels of her hands to her eyes. She remembers the wine bar, Luke’s face coming toward her, his voice low but insistent – It’s difficult to separate the two, isn’t it? – and his hand on hers, which was hot. She remembers running to the car, and curling in the backseat like a child.

She is starving. She crawls from the backseat to the front and scrabbles around in the passenger seat for yesterday’s leftovers. The apples have turned spongy and brown, but she eats them anyway, as well as the warm, puckered grapes. She avoids the car mirror but catches sight of herself, accidentally, in the passenger side window – her hair like Einstein’s, her mouth drooping open – before she looks away and finds her keys.

At her condo, she strips off her clothes, depositing everything directly in the washing machine, and showers for so long the water turns cool. She pulls on her bathrobe – pink and ridiculously fluffy, a gift from Gertie, something Varya never would have bought for herself – and takes as much Advil as she thinks her body can stand. Then she climbs into bed and sleeps again.

It’s mid-afternoon when she wakes up. Now that she is no longer purely exhausted, she feels a bolt of panic and knows she cannot spend the rest of the day at home. She dresses quickly. Her face is pale and birdlike and her silver hair sticks up in tufts. She wets her hands and smooths it down, then wonders why: the only people at the lab on Saturdays are the animal techs, and anyway, Varya will put a hair cover on as soon as she arrives. She doesn’t usually eat lunch, but today she grabs another baggie from the refrigerator and eats the hardboiled eggs as she drives.

As soon as she enters the lab, she feels calmer. She pulls on her scrubs and walks into the vivarium.

She wants to check on the monkeys. It still makes her nervous to be close to them, but she is sometimes beset by the fear that something will happen to them while she is gone. Nothing has, of course. Josie uses her mirror to look at the doorway and, when she sees Varya, lets the mirror drop. The infants skitter anxiously in their communal enclosure. Gus sits in the back of his cage. But the last cage – Frida’s cage – is empty.

‘Frida?’ Varya asks, absurdly; there is no proof that the monkeys understand their names, and yet she says it again. She leaves the vivarium and walks down the hallway, calling, until an animal technician named Johanna steps out of the kitchen.

‘She’s in isolation,’ Johanna says.

‘Why?’

‘She was plucking,’ says Johanna, rapidly. ‘I thought, in isolation, she might –’

But she does not finish, because Varya has already turned around.

The second floor of the lab is a square. Varya and Annie’s office is on the western side, the vivarium north. The kitchen is south, along with the procedure rooms, and the isolation chamber – as well as the janitor’s closet and the laundry room – is east. At six feet wide by eight tall, the isolation chamber is actually bigger than the monkeys’ normal cages. But it is devoid of enrichment, a place where disobedient animals are sent to be punished. Of course, there is nothing threatening about it, nothing overtly frightening. There is merely nothing interesting about it, either: it is a stainless steel cage with a small, square door for entry, which locks from the outside. It’s equipped with a food box and a water bottle. There are four inches between the floor and the bottom of the chamber, which has been drilled with holes to allow urine and waste to drop into a retractable pan.

‘Frida,’ says Varya. She looks into the chamber, the same place she brought Frida on the night of her arrival, when the monkey was only days old.

Now Frida faces the rear of the cage and rocks in place, hunching. Her back is bald in fist-sized areas where she pulled the hair out. Six months ago, she stopped grooming what fur she has, and the other animals keep away, sensing her weakness, repelled by it. She sits in a thin layer of rust-colored urine that has not yet drained into the pan.

‘Frida,’ repeats Varya, louder now, but soothingly. ‘Stop, Frida – please.’

When the monkey hears Varya’s voice, she turns her face to one side. In profile, her eyelid is glossy and lavender, her mouth an open half-moon. Then she grimaces. Slowly, she turns, but when she comes to face Varya, she does not stop: she continues to rotate, favoring her right limb, dragging the left. Two weeks ago, she bit her left thigh so badly it required stitches.

How did it happen? When Frida was young, she had more zest than any of the other monkeys. She could be Machiavellian in her social behavior, forging strategic alliances and stealing the more submissive animals’ food, but she was also charming and impossibly curious. She loved to be held: she reached through the bars for Varya’s waist, and Varya would occasionally let Frida out and carry her around the vivarium on one hip. The experience of being so close to her made Varya feel both frightened and ecstatic – frightened because of the fact of Frida’s contamination, and ecstatic because Varya could briefly, through layers of protective clothing, feel what it was like to be close to another animal, to be an animal herself.

A knock on the door. Johanna, Varya thinks, or Annie, though Annie rarely comes to the lab on weekends. Like Varya, she is both childless and unmarried. At thirty-seven, it’s hardly too late, but Annie does not want these things. ‘I lack for nothing,’ she said once, and Varya believed her. Annie’s populous Korean American family lives just over the bridge. She seems always to have a lover – sometimes male, sometimes female – and she executes these liaisons with the same confidence she does her research. Varya feels a motherly appreciation for Annie, as well as a motherly envy. Annie is the kind of woman Varya hoped to be: the kind who makes unconventional choices, and who is satisfied by them.

The knock comes again. ‘Johanna?’ calls Varya, rising to open the door.

But the person who faces her is Luke. His hair is tangled, dark with grease. His lips are chapped, and his face has a strange yellow cast. He wears the same clothes he did the day before. He must have slept in them, too. The sheet of calm Varya assembled this afternoon cracks down the center and falls.

‘What,’ she says, ‘are you doing here?’

‘Clyde let me in.’ Luke blinks. One of his hands is still on the doorknob, and the other, she sees, is trembling. ‘I need to talk to you.’

Frida has turned to face the wall and resumed her rocking. Varya hates her rocking, and she hates that Luke is here to see it. She turns away from him to lock the door of the isolation chamber. The process takes no more than two seconds, but before she is finished she hears a dull click and seizes. By the time she whips back to face him, he is stuffing his camera back in his bag.

‘Give that to me,’ she says, savagely.

‘No,’ says Luke, but his voice is small, like a young boy with a treasured belonging.

‘No? You weren’t authorized to take that photo. I’ll sue you.’

Luke’s face is filled not with the professional glee she expected but with fear. He clutches the backpack.

‘You’re not a journalist,’ Varya says. Her dread is acute, it is ringing. She thinks of the marmosets’ alarm calls. ‘Who are you?’

But he does not answer. He is fixed in the doorway, his body so still it would be statuesque if not for the still-quaking left hand.

‘I’ll call the police,’ she says.

‘Don’t,’ says Luke. ‘I –’

But he does not finish, and in that pause a thought rises in Varya unbidden. Let it be benign, she thinks, let it be benign, as if she is staring at the X-ray of a tumor and not into the face of an utter stranger.

‘You named me Solomon,’ he says.

And the pitch into darkness. At first she feels confusion: How? It isn’t possible. I would have known. Then the full impact, the flattening. Her vision smears.

For she stopped outside the Bleecker Street Planned Parenthood, those twenty-six years ago, and stood rooted to the ground as if by lightning. It was early February, dark and freezing at three thirty, but Varya’s body seared. Inside her was an unfamiliar flutter. She looked at the flatiron building in which the clinic was housed and wondered what would happen if she did not quash that flutter. She could make the choice she had planned to make; her life could continue on as it had been before the aberration and so remain symmetrical. Instead, she unbuttoned her coat to a flush of cold air. And then she turned around.