The corridor wasn’t as long as Clary had thought. Its darkness had made the distance seem impossible, but they had only been walking for a half hour or so when they broke out from the shadows and into a larger, lighted space.

They had been walking in silence and darkness, Clary lost in her thoughts—memories of the house she and Sebastian and Jace had shared, of the sound of the Wild Hunt roaring across the sky, of that piece of paper with the words “my beautiful one” on it. That hadn’t been romance; that had been respect. The Seelie Queen, the beautiful one. The Queen likes to be on the winning side of things, Clary, and that side will be ours, Sebastian had said to her once; even when she had reported that to the Clave, she had taken it as part of his bluster. She had believed along with the Council that the Fair Folk’s word that they were loyal was enough, that the Queen would at least wait to see which way the wind blew before she broke any alliances. She thought of the catch in Jace’s breath when he’d said a betrayal long-planned. Maybe none of them had considered it because they hadn’t been able to bear considering it: that the Queen would be so sure of Sebastian’s eventual victory that she would hide him in Faerie, where he could not be tracked. That she would help him in battle. Clary thought of the earth opening at the Adamant Citadel and taking Sebastian and the Endarkened down into it; that had been faerie magic: The Courts lay underground, after all. Why else had the Dark Shadowhunters who had attacked the Los Angeles Institute taken Mark Blackthorn? Everyone had assumed Sebastian was afraid of the vengeance of the Fair Folk, but he wasn’t. He was in league with them. He had taken Mark because he had faerie blood, and because of that blood, they thought Mark belonged to them.

In all her life she had never thought so much as she had in the past six months about blood and what it meant. Nephilim blood bred true; she was a Shadowhunter. Angel blood: It made her what she was, gifted her with the power of runes. It made Jace what he was, made him strong and fast and brilliant. Morgenstern blood: She had it, and so did Sebastian, and that was why he cared about her at all. It gave her a dark heart too, or did it? Was it Sebastian’s blood—Morgenstern and demon, mixed—that made him a monster, or could he have been changed, fixed, made better, taught otherwise, as the Lightwoods had taught Jace?

“Here we are,” said the Seelie Queen, and her voice was amused. “Can you guess the right road?”

They stood in a massive cave, the roof lost in shadow. The walls glowed with a phosphorescent shine, and four roads branched off from where they stood: the one behind them, and three others. One was clear and broad and smooth, leading directly ahead of them. The one on the left shone with green leaves and bright flowers, and Clary thought she saw the glimmer of blue sky in the distance. Her heart longed to go that way. And the last way, the darkest, was a narrow tunnel, the entrance wound about with spiked metal, and thornbushes lining the sides. Clary thought she could see darkness and stars at the end.

Alec laughed shortly. “We’re Shadowhunters,” he said. “We know the old tales. This is the Three Roads.” At Clary’s puzzled look he said, “Faeries don’t like their secrets to get out, but sometimes human musicians have been able to encode faerie secrets into ancient ballads. There’s one called ‘Thomas the Rhymer,’ about a man who was kidnapped by the Queen of Faerie—”

“Hardly kidnapped,” objected the Queen. “He came quite willingly.”

“And she took him to a place where three roads lay, and told him that one went to Heaven, and one went to Faerieland, and one went to Hell. ‘And see ye not that narrow road, so thick beset with thorns and briars? That is the path of righteousness, though after it but few inquires.’ ” Alec pointed toward the narrow tunnel.

“It goes to the mundane world,” said the Queen sweetly. “Your folk find it heavenly enough there.”

“That’s how Sebastian got to the Adamant Citadel, and had warriors backing him up that the Clave couldn’t see,” said Jace in disgust. “He used this tunnel. He had warriors hanging back here in Faerie, where they couldn’t be tracked. They came through when he needed them.” He gave the Queen a dark look. “Many Nephilim are dead because of you.”

“Mortals,” said the Queen. “They die.”

Alec ignored her. “There,” he said, pointing to the leafy tunnel. “That goes farther into Faerie. And that”—he pointed ahead—“is the road to Hell. That’s where we’re going.”

“I always heard it was paved with good intentions,” said Simon.

“Place your feet upon the way and find out, Daylighter,” said the Queen.

Jace twisted the tip of the blade in her back. “What will stop you from telling Sebastian we’ve come after him the moment we leave you?”

The Queen made no noise of pain; only her lips thinned. She looked old in that moment, despite the youth and beauty of her face. “You ask a fine question. And even if you kill me, there are those in my Court who will speak to him of you, and he will guess your intentions, for he is clever. You cannot evade his knowing, save you kill all the Fair Folk in my Court.”

Jace paused. He held the seraph blade in his hand, the tip pressed up against the Seelie Queen’s back. Its light flared up onto his face, carving out its beauty in peaks and valleys, the sharpness of cheekbones and the angle of jaw. It caught the tips of his hair and licked them with fire, as if he were wearing a crown of burning thorns.

Clary watched him, and the others did as well, silently, giving him their trust. Whatever decision he made, they would stand behind it.

“Come, now,” said the Queen. “You do not have the stomach for so much killing. You were always Valentine’s gentlest child.” Her eyes lingered a moment on Clary, gleeful. You have a dark heart in you, Valentine’s daughter.

“Swear,” said Jace. “I know what promises mean to your people. I know you cannot lie. Swear you will say nothing of us to Sebastian, nor will you allow anyone in your court to do the same.”

“I swear,” said the Queen. “I swear that no one in my court by word or deed will tell him that you came here.”

Jace stepped away from the Queen, lowering his blade to his side. “I know you think you are sending us to our deaths,” he said. “But we will not die so easily. We will not lose this war. And when we are victorious, we shall make you and your people bleed for what you have done.”

The Queen’s smile left her face. They turned away from her and started down the path to Edom, silently; Clary looked over her shoulder once as they went, and saw only the outline of the Queen, motionless, watching them go, her eyes burning.

The corridor curved far away into the distance, seeming as if it had been hollowed out of the rock around it by fire. As the five of them went forward, moving in total silence, the pale stone walls around them darkened, stained here and there by streaks of charcoaled blackness, as if the rock itself had burned. The smooth floor began to give way to a rockier one, grit crunching under their boot heels. The phosphorescence in the walls started to dim, and Alec drew his witchlight from his pocket and raised it overhead.

As the light rayed out from between his fingers, Clary felt Simon, beside her, stiffen.

“What is it?” she whispered.

“Something moving.” He jabbed a finger in the direction of the shadows ahead. “Up there.”

Clary squinted but saw nothing; Simon’s vampire eyesight was better even than a Shadowhunter’s. As quietly as she could she drew Heosphoros from her belt and paced a few steps ahead, keeping to the shadows at the sides of the tunnel. Jace and Alec were deep in conversation. Clary tapped Izzy on the shoulder and whispered to her, “There’s someone here. Or something.”

Isabelle didn’t reply, only turned to her brother and made a gesture at him—a complicated movement of fingers. Alec’s eyes showed his comprehension, and he turned immediately to Jace. Clary remembered the first time she’d seen the three of them, in Pandemonium, years of practice melding them into a unit that thought together, moved together, breathed together, fought together. She couldn’t help but wonder if, no matter what happened, no matter how dedicated a Shadowhunter she became, she would always be on the fringes—

Alec swung his hand down suddenly, dousing the light. A flash and a spark, and Isabelle was gone from Clary’s side. Clary spun around, holding Heosphoros, and heard the sounds of a scuffle: a thump, and then a very human yelp of pain.

“Stop!” Simon called, and light exploded all around them. It was as if a camera flash had gone off. It took a moment for her eyes to adjust to the new brightness. The scene filled in slowly: Jace holding his witchlight, the glow radiating around him like the light of a small sun. Alec, his bow raised and notched. Isabelle, the handle of her whip tight in one hand, the whip itself curled around the ankles of a slight figure hunched against the cave wall—a boy, with pale-blond hair that curled over his slightly pointed ears—

“Oh, my God,” Clary whispered, shoving her weapon back into her belt and pressing forward. “Isabelle—stop. It’s all right,” she said, moving toward the boy. His clothes were torn and dirty, his feet bare and black with filth. His arms were bare, too, and on them were the marks of runes. Shadowhunter runes.

“By the Angel.” Izzy’s whip slithered back into her grasp. Alec’s bow fell to his side. The boy lifted his head and scowled.

“You’re a Shadowhunter?” Jace said in an incredulous tone.

The boy scowled again, more ferociously. There was anger in his look, but more than that, there was grief and fear. There was no doubting who he was. He had the same fine features as his sister, the same angled chin and hair like bleached wheat, curling at the tips. He was about sixteen, Clary remembered. He looked younger.

“It’s Mark Blackthorn,” Clary said. “Helen’s brother. Look at his face. Look at his hand.”

For a moment, Mark looked confused. Clary touched her own ring finger, and his eyes lit with comprehension. He held out his thin right hand. On the fourth finger the family ring of the Blackthorns, with its design of intertwined thorns, glittered.

“How did you get here?” Jace said. “How did you know how to find us?”

“I was with the Hunters underground,” Mark said in a low voice. “I heard Gwyn talking to some of the others about how you’d shown up in the Queen’s chamber. I sneaked away from the Hunters, they weren’t paying attention to me. I was looking for you and I ended up—here.” He gestured to the tunnel around them. “I had to talk to you. I had to know about my family.” His face was in shadow, but Clary saw his features tighten. “The faeries told me they were all dead. Is it true?”

There was a shocked silence, and Clary read the panic in Mark’s expression as his eyes darted from Isabelle’s downcast eyes, to Jace’s blank expression, to Alec’s tight posture.

“It’s true,” Mark said then, “isn’t it? My family—”

“Your father was Turned. But your brothers and sisters are alive,” Clary said. “They’re in Idris. They escaped. They’re fine.”

If she had expected Mark to look relieved, she was disappointed. He went white. “What?”

“Julian, Helen, the others—they’re all alive.” Clary put her hand on his shoulder; he flinched away. “They’re alive, and they’re worried about you.”

“Clary,” Jace said, a warning in his voice.

Clary shot a look at him over her shoulder; surely telling Mark his siblings were alive was the most important thing?

“Have you eaten anything, drunk anything since the Fair Folk took you?” Jace asked, moving to peer into Mark’s face. Mark jerked away, but not before Clary heard Jace’s sharp intake of breath.

“What is it?” Isabelle demanded.

“His eyes,” Jace said, raising his witchlight and shining it into Mark’s face. Mark scowled again but allowed Jace to examine him.

His eyes were large, long-lashed, like Helen’s; unlike hers, his were mismatched. One was Blackthorn blue, the color of water. The other was gold, hazed through with shadows, a darker version of Jace’s own.

Jace swallowed visibly. “The Wild Hunt,” he said. “You’re one of them now.”

Jace was scanning the boy with his eyes, as if Mark were a book he could read. “Put your hands out,” Jace said finally, and Mark did so. Jace caught them and turned them over, baring the other boy’s wrists. Clary felt her throat tighten. Mark was wearing only a T-shirt, and his bare forearms were striped with bloody whip marks. Clary thought of the way she had touched Mark’s shoulder and he’d flinched away. God knew what his other injuries were, under his clothes. “When did this happen?”

Mark pulled his hands away. They were shaking. “Meliorn did it,” he said. “When he first took me. He said he’d stop if I ate and drank their food, so I did. I didn’t think it mattered, if my family was dead. And I thought faeries couldn’t lie.”

“Meliorn can,” said Alec grimly. “Or at least, he could.”

“When did this all happen?” Isabelle demanded. “The faeries only took you less than a week ago—”

Mark shook his head. “I’ve been with the Folk for a long time,” he said. “I couldn’t say how long.”

“Time runs differently in Faerie,” Alec said. “Sometimes faster, sometimes slower.”

Mark said, “Gwyn told me I belonged to the Hunt and I couldn’t leave them unless they allowed me to go. Is that true?”

“It’s true,” Jace said.

Mark slumped against the cave wall. He turned his head toward Clary. “You saw them. You saw my brothers and sisters. And Emma?”

“They’re all right, all of them, Emma, too,” Clary said. She wondered if it helped. He had sworn to stay in Faerie because he thought his family was dead, and the promise held, though it was based on a lie. Was it better to think you had lost everything, and to start over? Or easier to know that the people you loved were alive, even if you could never see them again?

She thought of her own mother, somewhere in the world beyond the end of the tunnel. Better to know they were alive, she thought. Better for her mother and Luke to be alive and all right, and for her never to see them again, than for them to be dead.

“Helen can’t take care of them. Not alone,” Mark said a little desperately. “And Jules, he’s too young. He can’t take care of Ty; he doesn’t know the things he needs. He doesn’t know how to talk to him—” He took a shuddering breath. “You should let me come with you.”

“You know you can’t,” said Jace, though he couldn’t look Mark in the face; he was staring at the ground. “If you’ve sworn fealty to the Wild Hunt, you’re one of them.”

“Take me with you,” Mark repeated. He had the stunned, bewildered look of someone who had been mortally injured but didn’t yet realize the extent of the injury. “I don’t want to be one of them. I want to be with my family—”

“We’re going to Hell,” Clary said. “We couldn’t bring you with us, even if you could leave Faerie safely—”

“And you can’t,” Alec said. “If you try to leave, you’ll die.”

“I’d rather die,” Mark said, and Jace’s head whipped up. His eyes were bright gold, almost too bright, as if the fire inside him were spilling out through them.

“They took you because you have faerie blood, but also because you have Shadowhunter blood. They want to punish the Nephilim,” Jace said, his gaze intent. “Show them what a Shadowhunter is made of; show them you aren’t afraid. You can live through this.”

In the wavering illumination of the witchlight, Mark looked at Jace. Tears had made their tracks through the dirt on his face, but his eyes were dry. “I don’t know what to do,” he said. “What do I do?”

“Find a way to warn the Nephilim,” Jace said. “We’re going into Hell, like Clary said. We might never come back. Someone has to tell the Shadowhunters the Fair Folk are not their allies.”

“The Hunters will catch me if I try to send a message.” The boy’s eyes flashed. “They’ll kill me.”

“Not if you’re fast and smart,” said Jace. “You can do it. I know you can.”

“Jace,” Alec said, his bow at his side. “Jace, we need to let him go before the Hunt notice he’s missing.”

“Right,” Jace said, and hesitated. Clary saw him take Mark’s hand; he pressed his witchlight into the boy’s palm, where it flickered, and then resumed its steady glow. “Take this with you,” said Jace, “for it can be dark in the land under the hill, and the years very long.”

Mark stood for a moment, the rune-stone in his hand. He looked so slight in the wavering light that Clary’s heart hammered a tattoo of disbelief—surely they could help him, they were Nephilim, they didn’t leave their own behind—and then he turned and ran, away from them, on soundless bare feet.

“Mark—” Clary whispered, and cut herself off; he was gone. The shadows swallowed him up, only the darting will-o’-the-wisp light of the rune-stone visible, until it too blended with the darkness. She looked up at Jace. “What did you mean, ‘the land under the hill’?” she asked. “Why did you say that?”

Jace didn’t answer her; he looked stunned. She wondered if Mark, brittle and orphaned and alone, reminded him somehow of himself.

“The land under the hill is Faerie,” said Alec. “An old, old name for it. He’ll be all right,” he said to Jace. “He will.”

“You gave him your witchlight,” Isabelle said. “You’ve always had that witchlight—”

“Screw the witchlight,” Jace said violently, and slammed his hand against the wall of the cave; there was a brief flare of light, and he drew his arm back. The mark of his hand was burned black into the stone of the tunnel, and his palm still glowed, as if the blood in his fingers were phosphorus. He gave an odd, choked laugh. “I don’t exactly need it, anyway.”

“Jace,” Clary said, and put her hand on his arm. He didn’t move away from her, but he didn’t react, either. She dropped her voice. “You can’t save everyone,” she said.

“Maybe not,” he said as the light in his hand dimmed. “But it would be nice to save someone for a change.”

“Guys,” Simon said. He’d been oddly quiet throughout the encounter with Mark, and Clary was startled to hear him speak now. “I don’t know if you can see it, but there’s something—something at the end of the tunnel.”

“A light?” Jace said, his voice edged with sarcasm. His eyes glittered.

“The opposite.” Simon moved forward, and after a hesitant moment Clary took her hand from Jace’s arm, and followed him. The tunnel went straight on ahead and then jogged slightly; at the curve she saw what Simon must have seen, and stopped dead.

Darkness. The tunnel ended in a whirling vortex of darkness. Something moved in it, shaping the dark like the wind shaping clouds. She could hear it too, the purr and rumble of the dark, like the sound of jet engines.

The others joined her. Together they stood in a line, watching the dark. Watching it move. A curtain of shadow, and beyond it the utter unknown.

It was Alec who spoke, staring, awed, at the moving shadows. The air that blew down the corridor was stinging hot, like pepper thrown into the heart of a fire. “This,” he said, “is the craziest thing we’ve ever done.”

“What if we can’t ever come back?” Isabelle said. The ruby around her neck was pulsing, glowing like a stoplight, illuminating her face.

“Then at least we’ll be together,” Clary said, and looked around at her companions. She reached out and took Jace’s hand, and Simon’s hand on the other side of her, and held them tight. “We go through together, and on the other side we stay together,” she said. “All right?”

None of them answered, but Isabelle took Simon’s other hand, and Alec took Jace’s. They all stood for a moment, staring. Clary felt Jace’s hand tighten on hers, a nearly imperceptible pressure.

They stepped forward, and the shadows swallowed them up.

“Mirror, my mirror,” said the Queen, placing her hand upon the mirror. “Show me my Morning Star.”

The mirror hung on the wall of the Queen’s bedroom. It was surrounded by wreaths of flowers: roses from which no one had cut away the thorns.

The mist inside the mirror coalesced, and Sebastian’s angular face looked out. “My beautiful one,” he said. His voice was calm and composed, though there was blood on his face and clothes. He was holding his sword, and the stars along the blade were dimmed with scarlet. “I am . . . somewhat occupied at the moment.”

“I thought you might wish to know that your sister and adoptive brother have just left this place,” said the Queen. “They found the road to Edom. They are coming to you.”

His face transformed with a wolfish grin. “And they didn’t make you promise not to tell me that they came to your court?”

“They did,” said the Queen. “They said nothing about telling you of leaving.”

Sebastian laughed.

“They killed one of my knights,” said the Queen. “Spilled blood before my throne. They are beyond my reach now. You know my people cannot survive in the poison lands. You will have to take my revenge for me.”

The light in his eyes changed. The Queen had always found what Sebastian felt for his sister, and Jace as well, to be something of a mystery, but then Sebastian himself was by far the greater mystery. Before he had come to make her his offer, she would never have considered a true alliance with Shadowhunters. Their peculiar sense of honor made them untrustworthy. It was Sebastian’s very lack of honor that made her trust him. The fine craft of betrayal was second nature to Fair Folk, and Sebastian was an artist of lies.

“I will serve your interests in all ways, my Queen,” he said. “In a short enough while your people and mine shall hold the reins of the world, and when we do, you may have revenge on any who have ever offended you.”

She smiled at him. Blood still stained the snow in her throne room, and she still felt the jab of Jace Lightwood’s blade against her throat. It was not a real smile, but she knew enough to let her beauty do her work for her, sometimes. “I do adore you,” she said.

“Yes,” said Sebastian, and his eyes flickered, their color like dark clouds. The Queen wondered idly if he thought of the two of them the way she did: lovers who, even while embracing, each held a knife to the other’s back, ready to stab and to betray. “And I do like to be adored.” He grinned. “I am glad they are coming. Let them come.”