Koré sits up, pushing Thea back. “I’m sorry, Mother,” she says, her voice low and, despite everything, still elegant. “I’m not feeling quite well . . . but I can still dance—” Then she breaks into a coughing fit.

Stepmother’s face snaps into a hard, flat-mouthed mask. She crosses the room to us. “You stupid girl. What did you do? You know how easily you take ill.”

“I’m sorry,” Koré gasps between coughs.

There’s a crack as Stepmother’s hand slaps her face. Thea yelps and I drag her away.

“You stupid little bitch,” says Stepmother. “You’ve wrecked all our chances. Do we mean nothing to you? Does your family mean nothing to you?”

Koré shrinks back. For the first time I can remember, she looks terrified.

Stepmother seizes a handful of her hair. “Look at me, girl. Why did you do it? Why did you do it?”

“I’m sorry, Mother,” she whispers. “I didn’t mean—”

Stepmother shakes her like a rag doll. “No daughter of mine would be so selfish. No daughter of mine. None.” Her mouth spasms, and then she shoves Koré against the wall. “Go to your room. Stay there till you rot.”

Thea whimpers, but I have my hand pressed over her mouth. There’s nothing we can do for Koré. There’s never anything we can do.

Koré wavers to her feet. Her eyes meet mine, and she nods fractionally: she understands. Then, head bowed, she stumbles out of the room.

Thea nearly breaks free of my grip, but I whisper in her ear, “The only way to help her is to make Stepmother happy.” And she goes limp. She’s stupid, but not stupid enough to think she can fight, and so I release her.

Stepmother opens the box of masks, pulls out Koré’s, and throws it into the fire. She watches the edges begin to blacken and curl; then she turns back to us.

“Come, Thea,” she says. “We’ll go to the ball together, and you’ll prove you are my true daughter when Lord Anax falls in love with you.”

Thea glances at me. Her eyes are wide and leaking tears. But she pulls herself up straight and bends her mouth into a smile.

“Of course, Mother,” she says. “I—I can’t wait.”

When I bring Koré a bowl of broth for supper, she’s wavering on her feet as she tries to put on her dress.

“Sit down,” I tell her.

“No,” she says, struggling with the buttons. “I must—Lord Anax—” She coughs again.

“He won’t be charmed by a girl who coughs in his face,” I say, grabbing her shoulders, and push her down to sit on the bed.

Koré glares up at me. “You don’t understand.”

“No. I don’t.” My chest feels full of ice and gravel. “You’ve driven yourself sick to win him, but even if he did marry you, do you think it would make Stepmother love you? Do you think she ever has?”

“No,” says Koré.

The low, flat syllable slices through my rage and leaves me staring at her like a gutted fish.

“But,” I say, and can find no more words.

“Mother can’t love me or Thea ever again,” says Koré. “I know that. I’ve always known.”

“Then why,” I ask slowly, “are you still trying to please her?”

“Because she got that way for my sake.”

“She stopped loving you because she loved you?”

Koré’s mouth twists into something like a smile. “No. She married your father because she loved us and it was the only way to keep us fed. She stopped loving us because she made a bargain with the Gentle Lord.”

Our eyes meet. I should feel dread or sadness to learn that someone else in the household has made the same ruinous, wicked bargain with the prince of demons and ruler of our world. But all I feel is a bright, desperate exultation: She knows what it’s like. She knows what it’s like. She knows.

“What happened?” I ask.

“Father died,” says Koré, and for a moment she lets the words sit between us as if they’re all the explanation I need. (Maybe they are. In the end, Mother died is the only thing that will ever need to be said of me.)

“He was rich,” Koré goes on, “but the way his estate was entailed—everything went to his cousin. We would have been reduced to living off his charity, except Mother had quarreled with him, so we had not even that. She married your father because it was the only way to keep a roof over our heads. But she couldn’t forget our father. The one she loved. It was driving her mad, grieving for him while pretending to love her new husband. She told me so and then she told me that she had a plan.” Koré’s fists clench. “She would call upon the Gentle Lord, and when he came, she would offer to pay him with all her best memories of her first husband, if in exchange he could make her love her second husband and his house. And he granted her wish. She loved her husband and his house. She loved them so much she had no room to love anything else, and when he died, it drove her mad.”

I think of the desperate way that Stepmother says the honor of our house. She’s as helplessly relentless as my own mother; I should have known that she, too, had made a bargain.

“And you think,” I say, “if you marry Lord Anax, it will make her happy? That’s why you’re striving so hard?”

A harsh laugh rips out of Koré and frays into coughing. “Oh, she’d be delighted at such an honor to our house,” she says when she has her voice again. “But it won’t make her happy. There’s nothing left in this world that can do that.” She looks up at me, and her face is no longer posed or scornful in the slightest. “But if I can marry well, I can get Thea out of this house. She won’t have to lie awake half the night, afraid the demons are finally going to crawl out of the corners and come for her. She won’t have to spend her days afraid that she’ll finally offend Mother too much. She won’t have to waste her time worrying about you. She’ll be safe and well fed and people won’t laugh at her—she’ll be able to marry somebody kind and be happy.”

I can’t seem to move. I’m not sure I can breathe. I knew my stepsisters must have heard the servants’ reports of something strange in the hallways, but it had never occurred to me that they might believe them, let alone realize that there were demons in the house. That they might be almost as frightened of their mother as I was. That they, too, might long for escape.