“Instead of whipping two Blackthorns,” she said, “you can whip a Carstairs. Wouldn’t that be better?”

Gwyn hadn’t moved at Iarlath’s order; now his eyes widened. Kieran drew in his breath.

“Julian told you he killed faeries during the Dark War,” she said. “But I have killed many more. I cut their throats; I wet my fingers with their blood. I’d do it again.”

“Silence!” Rage filled Iarlath’s voice. “How dare you brag of such things?”

She reached down and yanked up her shirt. Mark’s eyes widened as she dropped it to the ground. She was standing in front of all of them in just her bra and jeans. She didn’t care. She didn’t feel naked—she felt clothed in rage and fury, like a warrior from one of Arthur’s tales.

“Whip me,” she said. “Agree to it and this will end here. Otherwise I swear I will hunt you through the lands of Faerie unto eternity. Mark can’t, but I can.”

Iarlath said something exasperated in a language Emma didn’t know, turning to look at the ocean. Kieran moved forward as he did so, toward Julian’s crumpled form.

“Don’t you touch him!” Mark yelled, but Kieran didn’t look at him, just slid his hands under Julian’s arms and drew him away from the tree. He laid him down a few feet away, removing his own long tunic to wrap it around Jules’s unconscious, bleeding body.

Emma expelled a breath of relief. The sun felt hot on her naked back. “Do it,” she said. “Unless you are too cowardly to whip a girl.”

“Emma, stop,” said Mark. His voice was full of a terrible ache. “Let it be me.”

Iarlath’s eyes had brightened with a cruel light. “Very well, Carstairs,” he said. “Do as your parabatai did. Ready yourself for the whip.”

Emma saw Gwyn’s expression turn to one of sadness as she moved toward the tree. The bark, up close, was smooth and dark red-brown. It felt cool to the touch as she slid her arms around it. She could see the individual cracks in the bark.

She gripped the wood with her hands. She heard Mark call her name again, but it seemed to be coming from very far away. Iarlath moved to stand behind her.

The whip whistled as he raised it. She closed her eyes. In the darkness behind her eyelids, she saw Julian, and fire around him. Fire in the chambers of the Silent City. She heard his voice whisper the words, those old words from the Bible, taken and remade by Shadowhunters to form the parabatai oath.

Whither thou goest, I will go—

The whip came down. If she had thought she felt pain before, it was agony now. Her back felt as if it were being opened up by fire. She ground her teeth together to silence her scream.

Entreat me not to leave thee—

Again. The pain was worse this time. Her fingers bit into the wood of the tree.

Or to return from following after thee—

Again. She slid to her knees.

The Angel do so to me, and more also, if aught but death part thee and me.

Again. The pain rose up like a wave, blotting out the sun. She screamed, but she couldn’t hear herself—her ears were stoppered, the world crumpling, folding in on itself. The whip came down a fifth time, a sixth, a seventh, but now she barely felt it as the darkness swallowed her.

Cristina came out of Emma’s bedroom looking somber.

Mark caught a glimpse of the room before the door closed behind her: He saw Emma’s still form, looking small beneath a pile of heavy covers, and Julian sitting on the bed beside her. His brother’s head was bent, his dark hair falling to cover his face.

Mark had never seen him so miserable.

“Is she all right?” he asked Cristina. They were alone in the corridor. Most of the kids were still asleep.

Mark didn’t want to remember his brother’s face when Julian had woken up near the quickbeam and seen Mark kneeling over Emma’s body, her stele in his hand, drawing healing runes on her lacerated skin with the shaking, unpracticed hand of someone long unused to the language of angels.

He didn’t want to remember the way Julian had looked when they’d come inside, Mark carrying Cortana and Julian with Emma in his arms, her blood all over his shirt, her hair matted with it. He didn’t want to remember the way Emma had screamed when the whip came down, and the way she’d stopped screaming when she collapsed.

He didn’t want to remember Kieran’s face as Mark and Julian had raced back toward the Institute. Kieran had tried to stop Mark, had put his hand on his arm. His face had been bleached and pleading, his hair a riot of black and despairing blue.

Mark had shaken off his grip. “Touch me again with your hand and you will see it parted from your wrist forever,” he had snarled, and Gwyn had pulled Kieran away from him, speaking to him in a voice that was equal parts sternness and regret.

“Let him be, Kieran,” he said. “Enough has been done here this day.”

They’d carried Emma into her bedroom, and Julian had helped lay her down on the bed while Mark had gone to get Cristina.

Cristina hadn’t screamed when he’d awoken her, or even when she’d seen Emma in her torn and blood-soaked clothes. She had gone to work helping them: She’d put Emma into clean, dry clothes, had retrieved bandages for Jules, had washed the blood from Emma’s hair.

“She will be all right,” Cristina said now. “She will heal.”

Mark didn’t want to remember the way Emma’s skin had opened as the whip had come down, or the sound the whip made. The smell of blood mixing with the salt of the ocean air.

“Mark.” Cristina touched his face. He turned his cheek into her palm, involuntarily. She smelled like coffee and bandages. He wondered if Julian had told her everything—of Kieran’s suspicions of her, of Mark’s inability to protect his brother or Emma.

Her skin was soft against his; her eyes, upturned, were wide and dark. Mark thought of Kieran’s eyes, like fragments of the glass inside a kaleidoscope, shattered and polychromatic. Cristina’s were steady. Singular.

She brought her hand down the side of his jaw, her expression thoughtful. Mark felt as if his whole body were tightening into a knot.

“Mark?” It was Julian’s voice, low, from the other side of the door.

“You should go in to your brother.” Cristina lowered her hand, brushing his shoulder once, reassuringly. “This is not your fault,” she said. “It is not. You understand?”

Mark nodded, unable to speak.

“I will wake the children and tell them,” she said, and set off down the hall, her stride as purposeful as if she were in gear, though she was wearing a T-shirt and pajama bottoms.

Mark took a deep breath and pushed open the door to Emma’s bedroom.

Emma lay unmoving, her pale hair spread out over the pillow, her chest rising and falling with steady breaths. They had used sleep runes on her, as well as runes to kill pain, stop blood loss, and heal.

Julian was still sitting beside her. Her hand was limp on the blanket; Julian had moved his own hand close to hers, their fingers interlocking but not touching. His head was turned away from Mark’s; Mark could only see the hunched set of his shoulders, the way the vulnerable curve of the nape of his neck looked like the curve of Emma’s back as the whip came down.

He seemed very young.