"Neither can I walk away and leave you to die!"

There. Will had said it, said the word, admitted the possibility. Die.

"No one else can be trusted with this." Jem's eyes were bright, feverish, almost wild. "Do you think I don't know that if you do not go after her, no one will? Do you think it doesn't kill me that I cannot go, or at least go with you?" He leaned toward Will. His skin was as pale as the frosted glass of a lamp shade, and like such a lamp, light seemed to shine through him from some inner source. He slid his hands across the coverlet. "Take my hands, Will."

Numbly Will closed his hands around Jem's. He imagined he could feel a flicker of pain in the parabatai rune on his chest, as if it knew what he did not and was warning him of coming pain, a pain so great he did not imagine he could bear it and live. Jem is my great sin, he had told Magnus, and this, now, was the punishment for it. He had thought losing Tessa was his penance; he had not thought of how it would be when he had lost both of them.

"Will," Jem said. "For all these years I have tried to give you what you could not give yourself."

Will's hands tightened on Jem's, which were as thin as a bundle of twigs. "And what is that?"

"Faith," said Jem. "That you were better than you thought you were. Forgiveness, that you need not always punish yourself. I always loved you, Will, whatever you did. And now I need you to do for me what I cannot do for myself. For you to be my eyes when I do not have them. For you to be my hands when I cannot use my own. For you to be my heart when mine is done with beating."

"No," said Will wildly. "No, no, no. I will not be those things. Your eyes will see, your hands will feel, your heart will continue to beat."

"But if not, Will-"

"If I could tear myself in half, I would-that half of me might remain with you and half follow Tessa-"

"Half of you would be no good to either of us," said Jem. "There is no other I could trust to go after her, no other who would give of his own life, as I would, to save hers. I would have asked you to undertake this mission even if I had not known your feelings, but being certain that you love her as I do- Will, I trust you above all, and believe in you above all, knowing that as always your heart is twinned with mine in this matter. Wo men shi jie bai xiong di-we are more than brothers, Will. Undertake this journey, and you undertake it not for yourself alone but for both of us."

"I cannot leave you to face death alone," Will whispered, but he knew he was beaten; the sands of his will had run out.

Jem touched the parabatai rune on his shoulder, through the thin material of his nightshirt. "I am not alone," he said. "Wherever we are, we are as one."

Will rose slowly to his feet. He could not believe he was doing what he was doing, but it was clear that he was, as clear as the silver rim around the black of Jem's eyes. "If there is a life after this one," he said, "let me meet you in it, James Carstairs."

"There will be other lives." Jem held his hand out, and for a moment they clasped hands, as they had done during their parabatai ritual, reaching across twin rings of fire to interlace their fingers with each other. "The world is a wheel," he said. "When we rise or fall, we do it together."

Will tightened his grip on Jem's hand. "Well, then," he said, through a tight throat, "since you say there will be another life for me, let us both pray I do not make as colossal a mess of it as I have this one."

Jem smiled at him, that smile that had always, even on Will's blackest days, eased his mind. "I think there is hope for you yet, Will Herondale."

"I will try to learn how to have it, without you to show me."

"Tessa," Jem said. "She knows despair, and hope as well. You can teach each other. Find her, Will, and tell her that I loved her always. My blessing, for all that it is worth, is on you both."

Their eyes met and held. Will could not bring himself to say good-bye, or to say anything at all. He only gripped Jem's hand one last time and released it, and then turned and walked out the door.

The horses were stabled out behind the Institute-Cyril's territory during the daytime, where the rest of them rarely ventured. The stable had once been an old parish house, and the floor was of uneven stone, swept scrupulously clean. Stalls lined the walls, though only two were occupied: one by Balios and the other by Xanthos, both fast asleep with their tails switching slightly, in the manner of dreaming equines. Their mangers were packed with fresh hay, and shining tack lined the walls, polished to bright perfection. Will determined that if he should return from his mission alive, he would make sure to tell Charlotte that Cyril was doing an excellent job.

Will woke Balios with gentle murmurings and drew him from his stall. He had been taught to saddle and bridle a horse as a boy, before he had ever come to the Institute, and so he let his mind wander as he did it now, running the stirrups up the leathers, checking both sides of the saddle, reaching carefully beneath Balios to capture the cinch.

He had left no notes behind him, no messages for anyone in the Institute. Jem would tell them where he had gone, and Will had found that now, in this time when he most needed the words he usually found so easily, he could not reach them. He could not quite conceive that he might be saying good-bye, and so he ran over and over in his mind what he had packed in the saddlebags: gear, a clean shirt and collar (who knew when he might need to look like a gentleman?), two steles, all the weapons that would fit, bread, cheese, dried fruit, and mundane money.

As Will fastened the cinch, Balios lifted his head and whickered. Will's head whipped around. A slight feminine figure stood in the doorway of the stable. As Will stared, she raised her right hand, and the witchlight in it flared up, illuminating her face.

It was Cecily, a blue velvet cloak wrapped around her, her dark hair loose and free around her face. Her feet were bare, peeking out beneath the hem of the cloak. He straightened up. "Cecy, what are you doing here?"

She took a step forward, then paused on the threshold, glancing down at her bare feet. "I could ask of you the same."

"I like to talk to the horses at night. They make good company. And you should not be out and about in your nightgown. There are Lightwoods wandering these halls."

"Very funny. Where are you going, Will? If you are going to seek more yin fen, take me with you."

"I am not going to seek more yin fen."

Understanding dawned in her blue eyes. "You are going after Tessa. You are going to Cadair Idris."

Will nodded.

"Take me," she said. "Take me with you, Will."

Will could not look at her; he went to get the bit and bridle, though his hands shook as he took them down and turned back to Balios. "I cannot take you with me. You cannot ride Xanthos-you have not the training-and an ordinary horse would only slow our journey down."

"The carriage horses are automatons. You cannot hope to catch them up-"

"I do not expect to. Balios may be the fastest horse in England, but he must rest and sleep. I am already resigned. I shall not reach Tessa on the road. I can only hope to arrive at Cadair Idris before it is too late."

"Then let me ride after you and do not worry if you outpace me-"

"Be reasonable, Cecy!"

"Reasonable?" she flared. "All I see is my brother going away from me again! It has been years, Will! Years, and I came to London to find you, and now that we are together again, you are leaving!"

Balios stirred uneasily as Will fitted the bit into his mouth and slid the bridle up over his head. Balios did not like shouting. Will gentled him with a hand on his neck.

"Will." Cecily sounded dangerous. "Look at me, or I shall go wake the household and stop you, I swear that I will."

Will leaned his head against the horse's neck and closed his eyes. He could smell hay and horse, and cloth and sweat and some of the sweet scent of smoke that still clung to his clothes, from the fire in Jem's room. "Cecily," he said. "I need to know that you are here and as safe as you can be, or I cannot leave. I cannot fear for Tessa ahead on the road, and you behind me, or the fear will break me down. Already too many that I love are in danger."

There was a long silence. Will could hear the beat of Balios's heart under his ear, but nothing else. He wondered if Cecily had left, walked out while he was speaking, perhaps to rouse the household. He lifted his head.

But no, Cecily was still standing where she had been, the witchlight burning in her hand. "Tessa said that you called out for me once," she said. "When you were ill. Why me, Will?"

"Cecily." The word was a soft exhale. "For years you were my-my talisman. I thought I had killed Ella. I left Wales to keep you safe. As long as I could imagine you thriving and happy and well, the pain of missing you and Mother and Father was worth it."

"I never understood why you left," Cecily said. "And I thought the Shadowhunters were monsters. I could not understand why you had come here, and I thought-I always thought-that when I was old enough, I would come, and pretend I wished to be a Shadowhunter myself, until I could convince you to come home. When I learned of the curse, I did not know what to think anymore. I understood why you had come but not why you stayed."

"Jem-"

"But even if he dies," she said, and he flinched, "you will not come home to Mam and Dad, will you? You are a Shadowhunter, through and through. As Father never was. It is why you have been so stubborn about writing to them. You do not know how to both ask forgiveness and also say that you are not coming home."

"I can't come home, Cecily, or at least, it is not my home any longer. I am a Shadowhunter. It is in my blood."

"You know I am your sister, do you not?" she said. "It is also in my blood."

"You said you were pretending." He searched her face for a moment and said slowly, "But you are not, are you? I have seen you, training, fighting. You feel it as I did. As if the floor of the Institute is the first really solid ground under your feet. As if you have found the place you belong. You are a Shadowhunter."

Cecily said nothing.

Will felt his mouth twist into a sideways smile. "I am glad," he said. "Glad there will be a Herondale in the Institute, even if I-"

"Even if you do not come back? Will, let me come with you, let me help you-"

"No, Cecily. Is it not enough that I accept that you will choose this life, a life of fighting and danger, though I have always wanted greater safety for you? No, I cannot let you come with me, even if you hate me for it."

Cecily sighed. "Don't be so dramatic, Will. Must you always insist that people hate you when they obviously don't?"

"I am dramatic," said Will. "If I had not been a Shadowhunter, I would have had a future on the stage. I have no doubt I would have been greeted with acclaim."

Cecily did not appear to find this amusing. Will supposed he could not blame her. "I am not interested in your rendition of Hamlet," she said. "If you will not let me go with you, then promise me that if you go now-promise that you will come back?"

"I cannot promise that," Will said. "But if I can come back to you, I will. And if I do come back, I will write to Mother and Father. I can promise that much."

"No," said Cecily. "No letters. Promise me that if you do come back, you will return to Mother and Father with me, and tell them why you left, and that you do not blame them, and that you love them still. I do not ask that you go home to stay. Neither you nor I can ever go home to stay, but to comfort them is little enough to ask. Do not tell me that it is against the rules, Will, because I know all too well that you enjoy breaking those."

"See?" Will asked. "You do know your brother a little after all. I give you my word, that if all those conditions are met, I will do as you ask."

Her shoulders and face relaxed. She looked small and defenseless with her anger gone, though he knew she was not. "And Cecy," he said softly, "before I go, I wish to give you one more thing."

He reached into his shirt and lifted over his head the necklace Magnus had given him. It swung, gleaming rich ruby red, in the dim lights of the stables.

"Your lady's necklace?" Cecily said. "Well, I confess it does not suit you."

He stepped toward Cecily and drew the glittering chain over her dark head. The ruby fell against her throat as if it were made for her. She looked at him over it, her eyes serious. "Wear it always. It will warn you when demons are coming," Will said. "It will help keep you safe, which is how I want you, and help you be a warrior, which is what you want."

She put her hand against his cheek. "Da bo ti, Gwilym. Byddaf yn dy golli di."

"And I you," he said. Without looking at her again, he turned to Balios and swung himself up into the saddle. She stepped back as he urged the horse toward the stable doors and, bending his head against the wind, galloped out into the night.

Out of dreams of blood and metal monsters, Tessa woke with a start and a gasp.

She lay crouched like a child on the bench seat of a large carriage, whose windows were entirely covered with thick velvet curtains. The seat was hard and uncomfortable, with springs reaching to poke her sides through the material of her dress, which itself was torn and stained. Her hair had come down and hung in lank handfuls around her face. Across from her, huddled in the opposite corner of the carriage, sat a still figure, entirely covered in a thick black fur traveling cloak, its hood pulled down low. There was no one else in the carriage.

Tessa struggled upright, fighting a bout of dizziness and nausea. She put her hands on her stomach and tried to breathe deeply, though the fetid air inside the carriage did little to calm her stomach. She put her hands against her chest, feeling the sweat trickle down the bodice of her dress.

"Not going to be sick, are you?" said a rusty voice. "Chloroform does have that side effect, sometimes."

The hooded face creaked toward her, and Tessa saw the face of Mrs. Black. She had been too shocked on the steps of the Institute to make a real study of the visage of her erstwhile captor, but now that she could see it up close, she shuddered. The skin had a greenish tint, the eyes were veined in black, and the lips sagged, showing a view of gray tongue.

"Where are you taking me?" Tessa demanded. It was always the first thing heroines in Gothic novels asked when they were kidnapped, and it had always annoyed her, but she realized now that it actually made good sense. In this sort of situation the first thing you wanted to know was where you were going.