A cry broke from Clary’s throat. “Mom!”

“I sent them back to your world,” said Asmodeus. “Now you know.” He examined his nails.

Clary was panting, half with panic, half with rage. “How dare you—”

“Well, it’s what you wanted, isn’t it?” said Asmodeus. “There, you got the first two for free. The rest, well, it’ll cost you.” He sighed at the looks on the faces around him. “I’m a demon,” he said pointedly. “Really, what do they teach Nephilim these days?”

“I know what you want,” Magnus said in a strained voice. “And you can have it. But you must swear on the Morning Star to send all my friends back to Idris, all of them, and never to bother them again. They will owe you nothing.”

Alec stepped forward. “Stop,” he said. “No—Magnus, what do you mean, what he wants? Why are you talking like you’re not coming back to Idris with us?”

“There is a time,” said Asmodeus, “when we must all return to live in the houses of our fathers. Now is Magnus’s time.”

“‘In my father’s house are many mansions,’” Jace whispered; he looked very pale, and as if he might throw up. “Magnus. He can’t mean—he doesn’t want to take you back with him? Back to—”

“To Hell? Not precisely,” Asmodeus said. “As Magnus said, Edom is my realm. I shared it with Lilith. Then her brat took it over and laid waste to the grounds, destroyed my keep—it’s in slivers out there. And you murdered half the populace with the skeptron.” The last was addressed to Jace, rather petulantly. “It takes great energy to fuel a realm. We draw from the power of what we have left behind, the great city of Pandemonium, the fire we fell into, but there is a time when life must fuel us. And immortal life is the best of all.”

The numb heaviness weighing Clary’s limbs vanished as she snapped to attention, moving in front of Magnus. She nearly collided with the others. They had all moved just as she had, to block the warlock from his demon father, even Simon. “You want to take his life?” Clary asked. “That’s just cruel and stupid, even if you’re a demon. How could you want to kill your own child—”

Asmodeus laughed. “Delightful,” he said. “Look at them, Magnus, these children who love you and want to protect you! Who would ever have thought it! When you are buried, I will make sure they inscribe it on your tomb: Magnus Bane, beloved of Nephilim.”

“You won’t touch him,” Alec said, his voice like iron. “Maybe you’ve forgotten what it is we do, us Nephilim, but we kill demons. Even princes of Hell.”

“Oh, I know well what you do; my kinsman Abbadon you slew, and our princess Lilith you scattered to the winds of the void, though she will return. She always has a place in Edom. That is why I allowed her son to set himself up here, though I admit I did not realize what a mess he’d make.” Asmodeus rolled his eyes; Clary suppressed a shudder. Around the gold-green pupils the sclerae of his eyes were as black as oil. “I do not plan to kill Magnus. That would be messy and silly, and besides I could have had his death arranged at any time. It is his life freely given I want, for the life of an immortal has power, great power, and it will help me fuel my kingdom.”

“But he’s your son,” Isabelle protested.

“And he will remain with me,” said Asmodeus with a grin. “In spirit, you might say.”

Alec whirled on Magnus, who stood with his hands in his pockets, scowling. “He wants to take your immortality?”

“Exactly,” Magnus said.

“But—you’d survive? Just not be immortal anymore?” Alec looked wretched, and Clary couldn’t help feeling awful for him. After the reason Alec and Magnus had broken up, Alec certainly didn’t want or need to be reminded that he had once wanted Magnus’s immortality taken away.

“My immortality would be gone,” Magnus said. “All the years of my life would come on me at once. I would be unlikely to survive it. Almost four hundred years is quite a lot to take, even if you moisturize regularly.”

“You can’t,” Alec said, and there was a plea in his voice. “He said ‘a life given willingly.’ Say no.”

Magnus raised his head and looked up and over at Alec; it was a look that made Clary flush and glance away. There was so much love in it, mixed with exasperation and pride and despair. It was an unguarded look, and it felt wrong to see it. “I can’t say no, Alexander,” he said. “If I do, we all remain here; we’ll die anyway. We’ll starve, our ashes turned to dust to plague the demons of the realm.”

“Fine,” Alec said. “There isn’t any one of us who would give up your life to save ours.”

Magnus glanced around at the faces of his companions, dirty and exhausted and brutalized and despairing, and Clary saw the look on Magnus’s face change as he realized that Alec was right. None of them would give up his life to save theirs, even all of theirs.

“I’ve lived a long time,” Magnus said. “So many years, and no, it doesn’t feel like enough. I won’t lie and say it does. I want to live on—partly because of you, Alec. I have never wanted to live so much as I have these past few months, with you.”

Alec looked stricken. “We’ll die together,” he said. “Let me stay at least, with you.”

“You have to go back. You have to go back to the world.”

“I don’t want the world. I want you,” Alec said, and Magnus closed his eyes, as if the words almost hurt. Asmodeus watched as they spoke, avidly, almost hungrily, and Clary remembered that demons fed on human emotions—fear and joy and love and pain. Most of all, pain.

“You can’t stay with me,” Magnus said after a pause. “There will be no me; the demon will take my life force, and my body will crumble away. Four hundred years, remember.”

“ ‘The demon,’ ” Asmodeus said, and sniffed. “You could say my name, at least, while you’re boring me.”

Clary resolved then and there that she might hate Asmodeus more than any other demon she had ever met.

“Get on with it, my boy,” Asmodeus added. “I haven’t got all eternity to wait—and neither have you, anymore.”

“I have to save you, Alec,” Magnus said. “You and everyone you love; it’s a small price to pay, isn’t it, in the end, for all of that?”

“Not everyone I love,” Alec whispered, and Clary felt tears pressing behind her eyes. She had tried, tried so hard, to be the one who paid the price. It was not fair that Magnus should pay it; Magnus, who had the least part in the story of Nephilim and angels and demons and vengeance, compared to any of the rest of them; Magnus, who was only a part of it all because he loved Alec. “No,” Alec said. Through her tears Clary could see them clinging to each other; there was tenderness even in the curve of Magnus’s fingers around Alec’s shoulder as he bent to kiss him. It was a kiss of desperation and clutching more than passion; Magnus held on tightly enough for his fingers to bite into Alec’s arms, but in the end he stepped away, and turned toward his father.

“All right,” Magnus said, and Clary could tell he was bracing himself, nerving himself up as if he were about to throw his body onto a pyre. “All right, take me. I give you my life. I am—”