He went on to describe, in gruesome, painful detail, what happened next: How three of the remaining Shadowhunters were slaughtered by the demon—one disemboweled, one burned alive, one doused with acidic blood that dissolved him into dust. How the fourth survived only by the intercession of the warlocks, who returned him—disfigured by demonic burns that would never fade—to his people as a warning to stay away.

“Of course, we returned in even greater force, and repaid the warlocks tenfold for what they’d done to the villagers. But the far greater crime, that of Tobias Herondale, still called for vengeance.”

“The greater crime? Greater than slaughtering a bunch of Shadowhunters?” Simon said before he could stop himself.

“Demons and warlocks can’t help what they are,” Balogh said darkly. “Shadowhunters are held to a higher standard. The deaths of those three men sit squarely on the shoulders of Tobias Herondale. And he would have been punished in kind, had he ever been foolish enough to show his face again. He never did, but debts need repaying. A trial was held in absentia. He was judged guilty, and punishment was carried out.”

“But I thought you said he never came back?” Julie said.

“Indeed. So the punishment was carried out on his wife, in his stead.”

“His pregnant wife?” Marisol said, looking like she was about to be sick.

“Sed lex, dura lex,” Balogh said. The Latin phrase had been hammered into them from the first day at the Academy, and Simon was coming to hate the sound of it—so often was it used as an excuse for acting like monsters. Balogh steepled his fingers and contemplated the classroom, watching in satisfaction as his message came clear. This was how the Clave treated cowardice on the battlefield; this was justice under the Covenant. “The Law is hard,” Balogh translated for the hushed students. “But it is the Law.”

*    *    *

“Choose wisely,” Scarsbury warned, watching the students sift through the many pointy options the weapons room had to offer.

“How are we supposed to choose wisely when you won’t even tell us what we’re going up against?” Jon complained.

“You know it’s a vampire,” Scarsbury said. “You’ll learn more when you arrive on site.”

Simon slung a bow over his shoulders and selected a dagger for melee fighting; it seemed the weapon he was least likely to accidentally stab himself with. As the Shadowhunter students Marked themselves with runes of strength and agility and tucked witchlights into their pockets, Simon hooked a slim flashlight to one side of his belt and a portable flamethrower to the other. He touched the Star of David hanging on the same chain as Jordan’s pendant around his neck—it wouldn’t help much unless this vampire happened to be Jewish, but it made him feel just a little better. Like someone was looking out for him.

There was an electric charge of anticipation in the air that reminded Simon of being a little kid, preparing to go on a field trip. Of course, a visit to the Bronx Zoo or the sewage treatment center carried with it less chance of disembowelment, and instead of lining up to board a school bus, the students assembled themselves in front of a magical Portal that would transdimensionally carry them thousands of miles in the blink of an eye.

“You ready for this?” George asked him, grinning. Decked out in full gear with a longsword slung over his shoulder, Simon’s roommate looked every inch the warrior.

For a brief moment, Simon imagined himself saying no. Raising his hand, asking to be excused. Admitting that he didn’t know what he was doing here, that every fighting tactic he’d been taught had evaporated from his mind, that he would like to pack up his suitcase, Portal home, and pretend none of this had ever happened.

“As I’ll ever be,” he said—and stepped through the Portal.

From what Simon remembered, traveling by school bus was a filthy, undignified experience, rife with foul smells, spitballs, and the occasional embarrassing bout of motion sickness.

Traveling by Portal was significantly worse.

Once he’d regained his balance and his breath, Simon looked around—and gasped. No one had mentioned where they were Portaling to, but Simon recognized the block immediately. He was back in New York City—and not just New York but Brooklyn. Gowanus, to be specific, a thin stretch of industrial parks and warehouses lining a toxic canal that was less than a ten-minute walk from his mother’s apartment.

He was home.

It was exactly as he’d remembered it—and yet, wholly different. Or maybe it was just that he was wholly different, that after only two months in Idris, he’d forgotten the sounds and smells of modernity: the low, steady hum of electricity and the thick haze of car exhaust, the honking trucks and pigeon crap and piles of garbage that had for sixteen years formed the fabric of his daily life.

On the other hand, maybe it was because now that he could see through glamours, he could see the mermaids swimming in the Gowanus.

It was home and not home all at the same time, and Simon felt the same disorientation he had after his summer in the mountains at Camp Ramah, when he’d found himself unable to fall asleep without the sound of cicadas and Jake Grossberg’s snoring in the upper bunk. Maybe, he thought, you couldn’t know how much going away had changed you until you tried to go home.

“Listen up, men!” Scarsbury shouted, as the final student came through the Portal. They were assembled in front of an abandoned factory, its walls streaked with graffiti and its windows boarded up tight.

Marisol cleared her throat, loudly, and Scarsbury sighed. “Listen up, men and women. Inside this building is a vampire who’s broken the Covenant and killed several mundanes. Your mission is to track her down, and execute her. And I suggest you do so before sunset.”

“Shouldn’t the vampires be allowed to deal with this themselves?” Simon asked. The Codex had made it pretty clear that Downworlders were trusted to police themselves. Simon wondered whether that involved giving alleged rogue vampires a trial before they were executed.

How did I get here? he wondered—he didn’t even believe in the death penalty.

“Not that it’s any of your concern,” Scarsbury said, “but her clan has handed her over to us, so that you children can get a little blood on your hands. Think of it as a gift, from the vampires to you.”

Except “it” wasn’t an it at all, Simon thought.

“Sed lex, dura lex,” George murmured beside him, with an uneasy look, as if he was trying to convince himself.

“There’s twenty of you and one of her,” Scarsbury said, “and in case even those odds are too much for you, experienced Shadowhunters will be watching, ready to step in when you screw up. You won’t see them, but they’ll see you, and ensure that you come to no harm. Probably. And if any of you are tempted to turn tail and run, remember what you’ve learned. Cowardice has its price.”

*    *    *

When they were standing on the curb in the bright sunlight, the mission had sounded more than a little unsporting. Twenty Shadowhunters in training, all of them armed to the gills; one captured vampire, trapped in the building by steel walls and sunshine.

But inside the old factory, in the dark, imagining the flicker of motion and the glimmer of fangs behind every shadow, was a different story. The game no longer felt rigged in their favor—it no longer felt like much of a game at all.

The students split up into pairs, prowling through the darkness. Simon volunteered to guard one of the exits, hoping very much that this would prove similar to those gym class soccer games, where he’d spent hours guarding the goal and only a handful of times had to fend off a well-aimed kick.

Of course, each of those times, the ball had sailed over his head and into the net, losing the game for his team. But he tried not to think about that.