Drusher nodded. ‘You saw the map. We’re entering its territory now. Its hunting ground.’

‘How can you be so sure?’

‘Like I said, you saw the map. The thing is, we’re not talking about animal instinct. Not territory as a predator would understand it. We’re talking about orders.’

‘What? Orders?’

‘What is this place, Macks?’

‘The Commission of Works.’

‘And what’s behind it?’

‘Just rubble, Valentin.’

‘Yeah, but what was it before it was rubble?’

‘It was the main building of the Administratum here in Tycho. Before the tank shells levelled it.’

‘Exactly. The Administratum centre. Dead centre of the spread pattern. During the civil war, something was ordered to guard that vital point, secure it, defend it.’

Macks glared at him. ‘A man?’

Drusher shrugged. ‘Something. Something that’s still doing it. Macks, I glimpsed the killer in the Commission of Works, right after it killed Rimbaud. It was humanoid.’

Spread wide, the line of officers entered the ruins of the Administratum. Some parts of the ruin were two or three storeys tall, held up, crippled and crooked, by the ferrosteel bars stripped through the rockcrete.

There were weeds everywhere, flourishing. Tinsel-barb and frondwort, cabbage speculus and the limp foliage of climbing tracedy. The air was pungent with root-rot, stagnant water, mould.

Drusher slowly circled around. Macks was nearby, riotgun raised. He glanced left and saw Falken bending in under a broken doorway. To his right, Edvin was aiming his weapon at the overhung, plant-swathed walls.

Levy raised his clucking auspex box. ‘Getting something, very weak. It’s coming from the west.’

Falken nodded and disappeared. Macks hurried onwards. Mantagne covered her, glancing nervously up at the blooming foliage. Weapon clenched high, Roderin shuffled through a ruined archway.

‘Getting hot now, getting really hot,’ Levy called, lifting up his auspex, which was burring like a cicada.

‘Throne, it must be right on us!’

Falken’s gun went off. Once. Twice. Then another one echoed it. Macks started forward, running, and Drusher followed. Levy was right behind them. Mantagne rushed around to the other side of the wall.

There was a scream. Two more shots. Three.

Mantagne was dead. He had been sliced open from the scalp to the sternum. Blood was still spitting from his opened body, high into the air.

‘Throne!’ Macks cried, turning around. She heard Falken fire again, then Edvin. ‘Where is it? Where is it?’

Levy almost crashed into her from behind, following his auspex blindly.

‘Right there! There!’

Macks aimed and fired, once, twice, grinding back the slide each time. She put a huge hole in the facing wall.

Shots again, distant, from Falken and Edvin. Macks and Levy followed the sound. Pistol raised, Drusher turned the other way.