There was a scuffle at the hole, and then two of the infected dropped through, together, tangled and fighting as they fell crashing to the floor. With a series of barked shrieks, they disentangled themselves and ran at the agents, faces full of rage, the stench of infection preceding them.

Bryant met the first with a straight right cross, punching the monster from its feet. It slammed to the ground on its back, its face crushed and neck broken. Macy grabbed the second by the throat, holding it off at arm's length as it kicked and punched the air wildly. Macy took a moment to study the monster, and then, with an almost casual twist of her hand, broke its neck with a dull crack.

'That's not all of them,' Samuel warned.

There was another scuffle at the hole in ceiling. Three more infected jumped down, one after the other, and rushed forward. Macy hurled the limp body still in her hand. It crashed into the virus victims, knocking them to the carpet. The twins advanced, and the infected died before they could get to their feet.

No more followed. The air reeked of decay.

'Shit,' Bryant said. He was staring at the blood covering his gauntlets. He seemed agitated, desperate to clean it away. 'Get it off me!'

'Stop panicking,' Macy snapped. 'The virus is magical. Hamir said it dies with the carrier—'

'Shut up,' Samuel said. His voice was low but sliced the air like a blade.

His magic was still active.

As he heard a hard thump, Samuel spun around, aiming the revolver at the stairwell door at the end of the hallway. When it didn't open, he moved forwards, gesturing to the twins to keep back and stay silent. Laying a hand upon the dry and rough wooden surface, he closed his eyes and listened to his magic. It told him the door was locked and sturdy. But it warned him the immediate future would be grave if he opened it.

Samuel snapped his hand away as there came another thump on the other side of the door. This time, it was followed by the muffled cough-barks of the infected. Samuel stepped back as a fight broke out in the stairwell. The door shook and several quick screams were followed by abrupt silence. The silence was replaced by wet and angry gnawing. From the crack beneath the door, blood began soaking into the edge of the dusty carpet, making it a curious shade of grey through the goggles.

'How many do you think there are through there?' Macy said.

Samuel shrugged. He looked at the dead bodies in the hallway, and then up through the hole in the ceiling. His magic told him it was the safe way to continue on.

With the help of Bryant's interlaced fingers, Samuel was hoisted through the hole, and he climbed out onto the next floor of the building. He immediately checked the stairwell door to ensure it was locked on this level too. It was, and he wondered whether Fabian Moor had trapped his victims in the stairwell to wait until they had changed into servile golems.

There was another hole cut into the ceiling, and Samuel stared up into the last floor of the building as Macy and Bryant jumped up from the floor below to join him. Silently, the agents checked all the apartments.

'Why are the power stones missing?' Macy muttered to herself.

Certain now that there were no survivors, Samuel removed his charmed hat, rolled it up, and stuffed it into the inside pocket of his coat. The twins pulled back their hoods. Bryant rubbed the scar on his cheek as he always did when he was troubled. Out of habit, Samuel checked that his revolver's power stone was glowing and replaced the spent bullet. He then checked the spirit compass. The needle was slowly turning around the face again. The automaton spider was still outside the building, waiting to make its move.

Samuel took a breath and stood beneath the hole leading to the final floor. 'If Moor's here, he'll probably have golems with him.'

The twins gave Samuel a look as if to say that after what they had just dealt with, a bunch of fragile, slow-moving servants were no particular menace.

Samuel glared at them. 'Golems can use guns.'

Having enlightened them, Samuel looked up at the hole in the ceiling. 'And if Gene's still alive, he'll probably be up there too.'

Things were very different on the final floor of the shelter. This part of the dry and crumbling building felt almost alive, suffused with a strange darkness. Through the green glass lenses of the goggles, the darkness filled Samuel's vision, black yet luminous. The shadows of the third floor had become solid, tangible, chipped into a thousand million pieces that scuttled over threadbare carpet and crumbling plaster like a swarm of black-shelled beetles.

By the expressions on Macy and Bryant's faces, Samuel knew they could see the effect without the use of the goggles; and by the way they shifted, it was clear the twins could also feel the crackle of magic in the air.

The flow of the shadow-insects was converging on a closed door halfway down the hallway. Samuel walked to it, followed by his fellow agents. Curiously, the swarm on the floor parted beneath their feet, revealing the dry and worn carpet. With Macy and Bryant standing on either side of him, Samuel confronted the door. It was not coated in the strange darkness; rather the shadows crawled and scurried through the gap around the frame into the room beyond. Samuel considered the door, his prescient awareness stirring. A moment passed and Macy opened her mouth to speak.

Samuel didn't give her the chance.