“Much obliged, James,” Will said, without taking his eyes off Gabriel. “I appreciate the testament to my character.”

Jem shrugged. “It is the truth.”

Gabriel shot Jem a dark glare. “Stay out of this, Carstairs. This doesn’t concern you.”

Jem moved closer to the door, and to Will, who was standing perfectly still, matching Gabriel’s cold stare with one of his own. The hairs on the back of Tessa’s neck had begun to prickle. “If it concerns Will, it concerns me,” Jem said.

Gabriel shook his head. “You’re a decent Shadowhunter, James,” he said, “and a gentleman. You have your—disability, but no one blames you for that. But this—” He curled his lip, jabbing a finger in Will’s direction. “This filth will only drag you down. Find someone else to be your parabatai. No one expects Will Herondale to live past nineteen, and no one will be sorry to see him go, either—”

That was too much for Tessa. Without thinking about it she burst out indignantly, “What a thing to say!”

Gabriel, interrupted midrant, looked as shocked as if one of the tapestries had suddenly started talking. “Pardon me?”

“You heard me. Telling someone you wouldn’t be sorry if they died! It’s inexcusable!” She took hold of Will by the sleeve. “Come along, Will. This—this person—obviously isn’t worth wasting your time on.”

Will looked hugely entertained. “So true.”

“You—you—” Gabriel, stammering slightly, looked at Tessa in an alarmed sort of way. “You haven’t the slightest idea of the things he’s done—”

“And I don’t care, either. You’re all Nephilim, aren’t you? Well, aren’t you? You’re supposed to be on the same side.” Tessa frowned at Gabriel. “I think you owe Will an apology.”

“I,” said Gabriel, “would rather have my entrails yanked out and tied in a knot in front of my own eyes than apologize to such a worm.”

“Gracious,” said Jem mildly. “You can’t mean that. Not the Will being a worm part, of course. The bit about the entrails. That sounds dreadful.”

“I do mean it,” said Gabriel, warming to his subject. “I would rather be dropped into a vat of Malphas venom and left to dissolve slowly until only my bones were left.”

“Really,” said Will. “Because I happen to know a chap who could sell us a vat of—”

The door of the library opened. Mr. Lightwood stood on the threshold. “Gabriel,” he said in a freezing tone. “Do you plan to attend the meeting—your first Enclave meeting, if I must remind you—or would you rather play out here in the corridor with the rest of the children?”

No one looked particularly pleased by that comment, especially Gabriel, who swallowed hard, nodded, shot one last glare at Will, and followed his father back into the library, slamming the door shut behind them.

“Well,” said Jem after the door had closed behind Gabriel. “That was about as bad as I had expected it would be. Is this the first time you’ve seen him since last year’s Christmas party?” he asked, addressing the question to Will.

“Yes,” said Will. “Do you think I should have told him I missed him?”

“No,” said Jem.

“Is he always like that?” Tessa asked. “So awful?”

“You should see his older brother,” said Jem. “Makes Gabriel look sweeter than gingerbread. Hates Will even more than Gabriel, too, if that’s possible.”

Will grinned at that, then turned and began making his way down the corridor, whistling as he went. After a moment’s hesitation, Jem went after him, gesturing for Tessa to follow.

“Why would Gabriel Lightwood hate you, Will?” Tessa asked as they went. “What did you do to him?”

“It wasn’t anything I did to him,” Will said, stalking along at a rapid pace. “It was something I did to his sister.”

Tessa looked sideways at Jem, who shrugged. “Where there’s our Will, there’s a half-dozen angry girls claiming he’s compromised their virtue.”

“Did you?” Tessa asked, hurrying to keep up with the boys. There was simply only so fast you could walk in heavy skirts that swished around your ankles as you went. The delivery of dresses from Bond Street had come the day before, and she was only just beginning to get used to wearing such expensive stuff. She remembered the light dresses she’d worn as a little girl, when she’d been able to run up to her brother, kick him in the ankle, and dart away without him being able to catch her. She wondered briefly what would happen if she tried to do that to Will. She doubted it would work out to her advantage, though the thought had a certain appeal. “Compromise her virtue, I mean.”

“You have a lot of questions,” Will said, veering sharply to the left and up a set of narrow stairs. “Don’t you?”

“I do,” Tessa said, the heels of her boots clicking loudly on the stone steps as she followed Will upward. “What’s parabatai? And what did you mean about Gabriel’s father being a disgrace to Shadowhunters?”

“Parabatai in Greek is just a term for a soldier paired with a chariot driver,” said Jem, “but when Nephilim say it, we mean a matched team of warriors—two men who swear to protect each other and guard each other’s backs.”

“Men?” said Tessa. “There couldn’t be a team of women, or a woman and a man?”

“I thought you said women didn’t have bloodlust,” Will said without turning around. “And as for Gabriel’s father, let’s say that he has something of a reputation for liking demons and Downworlders more than he should. I would be surprised if some of the elder Lightwood’s nocturnal visits to certain houses in Shadwell haven’t left him with a nasty case of demon pox.”

“Demon pox?” Tessa was horrified and fascinated at the same time.

“He’s made that up,” Jem hastily reassured her. “Really, Will. How many times do we have to tell you there’s no such thing as demon pox?”

Will had stopped in front of a narrow door at a bend in the staircase. “I think this is it,” he said, half to himself, and jiggled the knob. When nothing happened, he took his stele out of his jacket and scrawled a black Mark on the door. It swung open, with a puff of dust. “This ought to be a storeroom.”

Jem followed him inside, and after a moment so did Tessa. She found herself in a small room whose only illumination was from an arched window set high in the wall above. Watery light poured through, showing a square space filled with trunks and boxes. It could have been any spare storage room anywhere, if it hadn’t been for what looked like piles of old weapons stacked in the corners—heavy rusty-looking iron things with broad blades and chains connected to spiked chunks of metal.

Will took hold of one of the trunks and moved it sideways to create a clear square of space on the floor. More dust puffed up. Jem coughed and shot him a reproachful look. “One would think you brought us here to murder us,” he said, “if it weren’t that your motivations for doing so seem cloudy at best.”

“Not murder,” Will said. “Hold on. I need to move one more trunk.”

As he pushed the heavy thing toward the wall, Tessa cast a sidelong look at Jem. “What did Gabriel mean,” she asked, pitching her voice too low for Will to hear, “‘your disability’?”

Jem’s silvery eyes widened fractionally, before he said, “My ill health. That’s all.”

He was lying, Tessa knew. He had the same sort of look Nate did when he lied—a little too clear-eyed a gaze to be a truthful one. But before she could say anything else, Will straightened up and announced, “There we are. Come sit down.”

He then proceeded to seat himself on the dusty stained floor; Jem went to sit beside him, but Tessa hung back for a moment, hesitant. Will, who had his stele out, looked up at her with a crooked smile. “Not going to join us, Tessa? I suppose you don’t want to ruin the pretty dress Jessamine bought you.”

It was the truth, actually. Tessa had no desire to wreck the nicest item of clothing she had ever owned. But Will’s mocking tone was more annoying than the thought of destroying the dress. Setting her jaw, she went and sat down opposite the boys, so that they formed a triangle between them.

Will placed the tip of the stele against the dirty floor, and began to move it. Broad dark lines flowed from the tip, and Tessa watched in fascination. There was something particular and beautiful about the way the stele scrawled—not like ink flowing from a pen, but more as if the lines had always been there, and Will was uncovering them.

He was halfway through when Jem made a noise of realization, clearly recognizing the Mark that his friend was drawing. “What do you—,” he began, but Will held up the hand he wasn’t drawing with, shaking his head.

“Don’t,” Will said. “If I make a mess of this, we could well fall through the floor.”

Jem rolled his eyes, but it didn’t seem to matter: Will was already finished, and was lifting the stele away from the design he had drawn. Tessa gave a little cry as the warped floorboards between them seemed to shimmer—and then became as transparent as a window. Scooting forward, forgetting entirely about her dress, she found herself staring through it as if through a pane of glass.

She was looking down into what she realized was the library. She could see the large round table and the Enclave seated at it, Charlotte between Benedict Lightwood and the elegant white-haired woman. Charlotte was easily recognizable, even from above, by the neat knotting of her brown hair and the quick movements of her small hands as she spoke.

“Why up here?” Jem asked Will in a low voice. “Why not the weapons room? It’s next to the library.”

“Sound radiates,” said Will. “Just as easy to listen from up here. Besides which, who’s to say one of them wouldn’t decide to pay a visit to the weapons room halfway through the meeting to see what we’ve in stock? It’s happened before.”

Tessa, staring down in fascination, realized that indeed she could hear the murmur of voices. “Can they hear us?”

Will shook his head. “The enchantment is strictly one-way.” He frowned, leaning forward. “What are they talking about?”

The three of them fell silent, and in the quiet the sound of Benedict Lightwood’s voice rose clearly to their ears. “I don’t know about this, Charlotte,” he said. “This whole plan seems very risky.”

“But we cannot simply let de Quincey go on as he has,” Charlotte argued. “He’s the head vampire of the London clans. The rest of the Night Children look to him for guidance. If we allow him to cavalierly break the Law, what message does that send to Downworld? That the Nephilim have grown lax in their guardianship?”

“Just so I understand,” Lightwood said, “you’re willing to take Lady Belcourt’s word that de Quincey, a longtime ally of the Clave, is actually murdering mundanes in his own house?”