At the far end of the corridor was another door, behind which Zidarov heard a slam, a crash, and the sound of running. He pushed against the door, feeling a sturdier lock-brace. He keyed up his jawsnapper to the maximum, and punched through the lock-box, smashing it into force-edged splinters. Then he kicked the door open and walked on through.

On the far side was another scruffy office unit. Boxes of parchment scrits had been heaped up against one wall. A cheap-looking desk occupied the centre of the space. The far wall, behind the desk, was taken up by a huge set of window panes, out of which the view went on forever.

A further set of doors on the right-hand wall was still swinging on its hinges. He barged his way through them, catching sight of a lone figure scampering down a service corridor, almost at the end.

Zidarov took aim, gauged the distance, and fired. The Tzar­ina sent a bullet whistling down the corridor, impacting against the far wall just to the right of the scurrying man’s shoulder. The fugitive screamed, throwing himself against the wall and crouching down with his arms over his head.

Zidarov went after him. Just as the man tried to get up, Zidarov grabbed him by his jacket lapels, lifted him to his feet, then slammed him hard against the bare rockcrete.

‘Don’t ever run,’ he said.

The man panicked. ‘I didn’t know! She didn’t tell me–’

‘You knew. You didn’t seem to want to talk.’

‘I can talk!’

‘Good. Let’s try that, then.’

Zidarov cuffed him hard, cracking the back of his head against the wall, then frogmarched him back down the service corridor, shoving him back into the office with the high windows. He found a swivel chair behind the desk, kicked it around to face him, then shoved the man into it.

‘Name,’ he said.

The man looked dumbly up at him, mouth hanging open. He had slack features, a weak chin, tufty hair. A bruise was beginning to develop over his left eye. He had crumbs on his chin and shirt. His armpits were damp. He was very scared.

‘Chaikos,’ he blurted. ‘Vassil Chaikos.’

Zidarov searched for another chair, and went to get it. As he did so, he looked around the room properly.

The Gargoza building, like all of those perched on the High Ridge, had been mounted on the lip of a giant fault in the urban landscape. The sheer edge fell one hundred and sixty feet straight down. Rows of receiving warehouses had been delved into the cliff face below them.