Shoving out with both hands as hard as he could, Samuel pushed the twins away from him in opposite directions. He dropped to one knee just as a hail of bullets ripped through the door with violet flashes of thaumaturgic bursts and flew over his head.

Samuel was sprayed with splinters of wood. The bullets made a thudding noise as they hit the scuttling shadows on the opposite wall. Samuel's deeper instincts guided him. Aiming up, his revolver spat four times. The hail of bullets ceased immediately.

Samuel sprang forward, kicking the door open and rolling into the room beyond. He came up shooting. Four more golems fell to the floor to join the two he had shot through the door. They thrashed and jerked upon hardened shadows, cracking and popping as their bodies began breaking into chunks of dry stone within their cassocks.

The revolver empty, Samuel holstered it, drew his rifle and primed the power stone. His magic took stock of the situation.

The apartment had been gutted. Door-shaped holes had been cut into the left and right walls, leading into the neighbouring apartments. Samuel's prescient awareness warned him that danger approached from the left side hole, into which all the shadows seemed to be crawling. He pressed his back to the wall next to the opening and waited.

Another golem stepped through, holding its pistol directly in front of it. Samuel drew his empty revolver and held the barrel to the golem's temple. Without a bullet to propel, the burst of thaumaturgy still punched a hole straight through the creature's head, and it crumbled to the floor. A second golem appeared, tripped over the ruins of the first and stumbled into the room.

Samuel's rifle spat a bullet into its face.

Wasting no time, not bothering to wait for the twins, Samuel darted through the hole in the wall into the apartment where the darkness congregated. He shot three more armed golems before they could fire, and smashed the head off a fourth with the butt of his rifle.

As Samuel quickly ejected the rifle's empty magazine and slapped a fresh one into place, he was vaguely aware of the twins entering the room he had just left. He heard Macy telling Bryant to check the other apartment through the hole on the right side wall before she stepped up beside Samuel. Her breath caught as she saw her fellow agent was now aiming his rifle at Fabian Moor.

The Genii sat cross-legged upon the floor, deep in a trance which the noise of fighting had not disturbed. Through the lenses of the goggles, he appeared to Samuel in perfect colour. His eyes were closed and face expressionless; his smooth, pale skin was only blemished by a patch of scarring upon his forehead. His long hair, white and straight, flowed over the shoulders of his black priest's cassock.

Samuel had wondered a hundred times what this creature of higher magic might look like. Never had he imagined that he would be facing someone so human-looking.

With his hands resting palm up upon his knees, Moor sat before a head-sized sphere of glass that floated two feet off the floor. The flow of swarming shadow-insects converged at the bottom of the sphere, where they were absorbed into the glass to fill it, thick and roiling. On the outside, the sphere was covered in a mesh of metal; and held by the mesh, at regular intervals, were a host of power stones, each as small as a little finger nail.

'Samuel,' Macy hissed, panicking. 'What are you waiting for? Just shoot the bastard!'

Fabian Moor's eyes snapped open. He gritted his teeth, and by the use of thaumaturgy propelled himself to his feet in a heartbeat.

Samuel squeezed the trigger. The power stone flashed and the rifle spat a thumb-sized metal slug. But the Genii had surrounded himself with a magical barrier. It melted the bullet to drops of molten lead that slapped to the floor, hissing and steaming. Samuel shot again but with the same results. His face grim, Fabian Moor raised a hand toward the agents of the Relic Guild. Macy bellowed and made to rush him.

She had taken no more than two steps when the window to the right exploded with a shower of shattered glass and broken framework. Samuel covered his face with an arm as the purple ghost of a giant spider crashed into the room.

'No!' Fabian Moor screeched.

Through the magically enhanced goggles, Samuel watched the automaton spider speed toward the Genii. Moor's hand glowed with thaumaturgy, but it was already too late. Before he could release whatever power he had summoned, the spider was upon him.

A dazzling blaze of energy filled the room as the spider cut through Moor's defensive barrier, burning so bright and magical through the lenses of the goggles that Samuel had to rip them from his face. He heard Macy swearing. When the slashes and streaks of thaumaturgy had cleared from his vision, Samuel saw that the spider had become visible.

The giant spider construct, with the head of a golem perched upon its melon-sized body, had coiled four of its long, thin legs around Fabian Moor's body, trapping his arms and squeezing his legs together in a cocoon of thaumaturgic metal. The tip of one leg had smoothed and flattened, moulding to the Genii's face, covering his mouth. Moor just had time to glare at Samuel, eyes full of hatred, before the automaton spider fizzed and became invisible once again, along with its captive. Glass shards cracked and jumped on the floor, plasterwork broke, as the spider clambered out of the window on its four remaining legs, spiriting the Genii away to his prison in the southern district.

Samuel dropped the goggles and shared a look of silent incredulity with Macy.

Incredulity turned to worry as the power stones surrounding the sphere of glass began to shine with bright, violet light. A sharp hissing filled the air, and the swarm of shadows fled the room as though being chased back to the places where sunlight could not reach. Abruptly, the hissing stopped. The power stones lost their light and became inert, clear crystals. The glass sphere dropped onto the threadbare carpet with a soft thump, nestling among the stony ruins of golems. No longer filled with oily blackness, it now contained an inert substance that looked much like murky water.

'Is ... that it?' Macy said. 'We succeeded?'

Samuel suspected her expression of dubious astonishment only mirrored his own. 'We'd better get this thing back to Hamir,' he said, indicating the glass sphere.

Macy nodded uncertainly. She bent down, paused, and then tentatively picked it up. 'Bryant!' she shouted, studying the sphere. 'We got him!'

When Bryant replied, his voice was full of anguish. 'Macy, Samuel.' A pause. 'You'd better come here.'

With Macy carrying the sphere under one arm, the two agents rushed from the room, crossed the apartment where broken golems littered the carpet, and went through the hole in the wall to join Bryant.

They found him on his knees, tears in his eyes, leaning over a figure on the floor who was shaking and moaning. Bryant looked back at his sister and Samuel.

'I don't know what to do,' he said.

Samuel holstered his rifle, pushed Bryant out of the way, and crouched down beside the Relic Guild agent called Gene.

The frail apothecary was naked, stripped of clothes and dignity, and secured to the floor by chains connected to a metal brace around his neck. Gene's jaundiced eyes found Samuel's and he grabbed his hand.

'S-Samuel,' he said from between chattering teeth. 'I-I'm sorry. I tried to fight him ... b-but he was too p-powerful.'

'It's all right, Gene,' Samuel said. 'You—'

'No, you don't ... understand.' Gene was weeping now. 'I-I gave you up, S-Samuel. All of you. Moor knows ... Moor knows who every a-agent of the Relic Guild is—'

Gene groaned in pain, and Samuel tightened his grip on his hand.

'Gene, listen to me. Did you tell Moor how to enter the Nightshade?'

'Don't ... Don't know ...'

The apothecary's skin was slimy, but not from sweat. His whole body was coated with a sticky excretion that emitted a sterile pungency. There was a bite wound on his neck, and it was obvious that Gene was using his magic, generating all manner of antidotes from the chemicals and minerals in his body, in a desperate attempt to fight the effects of Fabian Moor's virus – a fight he was losing.

'There's no cure,' Gene hissed, anger fuelling his normally gentle voice. 'I-I don't want to become a golem, Samuel. B-But I can't help myself. Please ... stop me. I-I already want to kill you.'

A new tone was lacing Gene's weak voice now, like a distant scream. Black veins were trying to criss-cross his skin; they emerged and faded as they fought with Gene's chemical magic. Samuel's prescient awareness issued a warning: it was time to put distance between him and the apothecary.

As Gene began thrashing on the floor, choking and coughing, Samuel dropped his hand, and took several quick steps backwards. Macy and Bryant remained behind him. Samuel drew his rifle, but he couldn't bring himself to prime the power stone, to do what he knew was necessary.

Gene stopped thrashing and glared with yellow eyes filled with animal rage. He clenched long teeth set in receding gums. 'Do it, you bastard!' His words came as shrieks. 'Don't be a coward!'

Black veins began spreading over his skin.

Samuel thumbed the power stone and took aim. 'I'm so sorry, Gene,' he whispered.

The apothecary screamed, straining against his chains as he tried to rise, to attack, to feed on the blood of his fellow agents.

Samuel's rifle spat and the bullet burst Gene's head.

The fleeting moment of stillness was shattered when Bryant shouted with fury and punched a hole in the wall. Macy laid a hand on the barrel of Samuel's rifle, gently coaxing him to lower it. He was vaguely aware of her telling him he had done only what had to be done.

Zero tolerance.

'You'd better report to Gideon,' he heard himself tell the twins in an empty, cold voice.

'What about the infected locked in the stairwell?' Macy said. 'We can't leave them here.'

'I'll deal with them,' Samuel replied. He couldn't take his eyes off the corpse of the old apothecary. 'I'll meet you back at the Nightshade.'

The twins were silent and didn't move.

'I don't need your help to clear the stairwell,' Samuel said. There was no argument in his voice, no willingness to debate the matter; it was a simple statement. 'Just go.'

One of the twins, probably Macy, patted him on the shoulder, and they left without a further word.

Samuel didn't know how long he stood staring at Gene's body before he set fire to the dry and decaying homeless shelter, but by the time he stood outside, watching the building burn, the morning sun had passed its zenith in the sky and was descending into the afternoon.