The Deumas roared again and lurched toward James, drool spilling from its mouth in long strings of greenish slime.

James swung his arm back, ready to throw his first knife. The demon’s eyes fixed on him for a moment. They were coruscating, green and black, filled with a hate that turned suddenly into something else.

Something like recognition. But demons, at least the lesser kind, didn’t recognize people. They were vicious animals driven by pure greed and hatred. As James hesitated in surprise, the ground under him seemed to lurch. He had only a moment to think, Oh no, not now, before the world went gray and silent. The buildings around him had turned to ragged shadow, the sky a black cave speared with white lightning.

He closed his right hand around his knife—not the handle, but the blade. The jolt of pain was like a slap to the face, snapping him out of a stupor. The world came rushing back at him in all its noise and color. He barely had time to register that the Deumas was in midair, claws extended toward him, when a swirl of cords whipped through the sky, entangling the demon’s leg and yanking it backward.

Thomas! James thought, and indeed, his massively tall friend had appeared behind the Deumas, armed with his bolas. Behind him was Christopher, armed with a bow, and Matthew, a seraph blade blazing in his hand.

The Deumas hit the ground with another roar, just as James let both his knives fly. One plunged into the demon’s throat, the other into its forehead. Its eyes rolled back, it spasmed, and James suddenly remembered what it was he’d read about Deumas demons.

“Matthew—” he began, just as the creature burst apart, showering Thomas, Christopher, and Matthew in ichor and burnt bits of what could only be described as goo.

Messy, James recalled belatedly. Deumas demons were notably messy. Most demons vanished when they died. Not Deumas demons.

They exploded.

“How—wha—?” Christopher stuttered, at a clear loss for words. Slime dripped off his pointed nose and gold-rimmed spectacles. “But how…?”

“Do you mean how is it possible that we finally tracked down the last demon in London and it was also the most disgusting?” James was surprised by how normal his voice sounded: he was already shaking off the shock of his glimpse into the shadow realm. At least his clothes were untouched: the demon seemed to have exploded mostly over the other end of the alley. “Ours is not to question why, Christopher.”

James had a feeling his friends were gazing at him resentfully. Thomas rolled his eyes. He was scrubbing at himself with a handkerchief that was also half-burnt and covered in ichor, so it was doing little good.

Matthew’s seraph blade had begun to sputter. Seraph blades, infused with the energy of angels, were often a Shadowhunter’s most trusted weapon and best defense against demons, but it was still possible to drown one in enough ichor. “This is an outrage,” Matthew said, tossing the extinguished blade aside. “Do you know how much I spent on this waistcoat?”

“No one told you to go out patrolling for demons dressed like an extra from The Importance of Being Earnest,” said James, tossing him a clean handkerchief. As he did, he felt his hand sting. There was a bloody cut across his palm from the blade of the knife. He closed his hand into a fist to prevent his companions from seeing it.

“I don’t think he’s dressed like an extra,” said Thomas, who had turned his attention to cleaning off Christopher.

“Thank you,” said Matthew with a slight bow.

“I think he’s dressed like a main character.” Thomas grinned. He had one of the kindest faces James had ever known, and gentle hazel eyes. None of which meant he didn’t enjoy mocking his friends.

Matthew mopped at his dull gold hair with James’s handkerchief. “This is the first time in a year that we’ve patrolled and actually found a demon, so I’d supposed that my waistcoat would probably survive the evening. It’s not as if any of you are wearing gear either.”

It was true that Shadowhunters usually hunted in gear, a sort of flexible armor made of a tough, leatherlike black material resistant to ichor, blades, and the like, but a lack of reliable demonic presence on the streets had made them all a bit lax about rules.

“Stop scrubbing at me, Thomas,” said Christopher, windmilling his arms. “We should go back to the Devil and clean up there.”

There was a murmur of assent among the group. As they picked their sticky way back to the main street, James considered the fact that Matthew was right. James’s father, Will, had often told him about the patrols he used to do with his parabatai, Jem Carstairs—now James’s uncle Jem—back when they had battled demons nearly every night.

James and other young Shadowhunters still faithfully patrolled the streets of London, seeking out demons that might harm the mundane population, but in the last few years demon appearances had been few and far between. It was a good thing—of course it was a good thing—but still. It was decidedly odd. Demon activity was still normal as far as the rest of the world was concerned, so what made London special?

There were plenty of mundanes out and about on the streets of the city, though the hour was late. None glanced at the bedraggled group of Shadowhunters as they made their way down Fleet Street; their glamour runes made them invisible to all eyes not gifted with the Sight.

It was always strange to be surrounded by a humanity that did not see you, James thought. Fleet Street was home to the newspaper offices and law courts of London, and everywhere were brightly lit pubs, with print workers and barristers and law clerks, who kept late hours, drinking into the dawn light. The Strand nearby had spilled the contents of its music halls and theaters, and well-dressed groups of young people, laughing and boisterous, chased the last omnibuses of the night.

The bobbies were out working their beats too, and those denizens of London unfortunate enough to have no homes to go to crouched muttering around cellar vents that sent up drifts of warm air—even in August the nights could be damp and chilly. As they passed a group of such huddled figures, one looked up, and James caught a glimpse of the pale skin and glittering eyes of a vampire.

He looked away. Downworlders weren’t his business unless they were breaking Clave Law. And he was tired, despite his energy Marks: it always drained him to be dragged into that other world of gray light and black ragged shadows. It was something that had been happening to him for years: a remnant, he knew, of his mother’s warlock blood.

Warlocks were the offspring of humans and demons: capable of using magic but not of bearing runes or using adamas, the clear crystalline metal from which steles and seraph blades were carved. They were one of the four branches of Downworlders, along with vampires, werewolves, and the fey. James’s mother, Tessa Herondale, was such a warlock, but her mother had been not just human but a Shadowhunter. Tessa herself had once possessed the power to shape-shift and take on the appearance of anyone, living or dead: a power no other warlock had. She was unusual in one other way as well: warlocks could not have children. Tessa was an exception. Everyone had wondered what this would mean for James and his sister, Lucie, the first-ever known grandchildren of a demon and a human being.

For many years, it appeared to have meant nothing. Both James and Lucie could bear Marks and seemed to have the abilities of any other Shadowhunter. They could both see ghosts—like the Institute’s chatty phantom-in-residence, Jessamine—but that was not uncommon in the Herondale family. It seemed they might both be blessedly normal, or at least as normal as a Shadowhunter could be. Even the Clave—the governing body of all Shadowhunters—had seemed to forget about them.

Then, when James was thirteen, he first traveled into the shadow realm. One moment he had been standing on green grass: the next, charred earth. A similarly scorched sky arced above him. Twisted trees emerged from the ground, ragged claws grasping at the air. He had seen such places in woodcuts in old books. He knew what he was looking at: a demon world. A Hell dimension.

Moments later he had been jerked back to earth, but his life had never been the same again. For years the fear had been there that he might at any moment hurtle back into shadow. It was as if an invisible rope connected him to a world of demons, and at any moment the rope could be pulled taut, snatching him out of his familiar environment and into a place of fire and ash.

For the last few years, with his uncle Jem’s help, he’d thought he had it under control. Though it had been only a few seconds, tonight had shaken him, and he was relieved when the Devil Tavern appeared before them.

The Devil made its home at No. 2 Fleet Street, next to a respectable-looking print shop. Unlike the shop, it was glamoured so that no mundanes could see it or hear the raucous noises of debauchery that poured from the windows and the open doors. It was half-timbered in the Tudor style, the old wood ratty and splintering, kept from falling down by warlocks’ spells. Behind the bar, werewolf owner Ernie pulled pints: the crowd was a mix of pixies and vampires and lycanthropes and warlocks.

The usual welcome for Shadowhunters in a place like this would have been a cold one, but the patrons of the Devil Tavern were used to the boys. They greeted James, Christopher, Matthew, and Thomas with yells of welcome and mockery. James stayed in the pub to collect drinks from Polly, the barmaid, while the others tramped upstairs to their rooms, shedding ichor on the steps as they went.

Polly was a werewolf, and had taken the boys under her wing when James had first rented out the attic rooms three years ago, wanting a private bolt-hole he and his friends could retreat to where their parents wouldn’t be hovering. She was the one who’d first taken to calling them the Merry Thieves, after Robin Hood and his men. James suspected he was Robin of Locksley and Matthew was Will Scarlett. Thomas was definitely Little John.

Polly chuckled. “Almost didn’t recognize the lot of you when you tramped in here covered in whatever-you-call-it.”

“Ichor,” said James, accepting a bottle of hock. “It’s demon blood.”

Polly wrinkled her nose, draping several worn-looking dishcloths over his shoulder. She handed him an extra one, which he pressed against the cut on his hand. It had stopped bleeding but still throbbed. “Blimey.”