As soon as the power failed, green strip lights began pulsing gently on the floor, guiding the way to the exits. Merv and Scant moved quickly and purposefully. Scant steered the trolley and Merv made straight for Corporal Kelp.

Grub was pulling the video glasses from over his eyes.

‘Hey,’ he said, disorientated by the sudden darkness. ‘What’s going on here?’

‘Power failure,’ said Merv, bumping into him with calculated clumsiness. ‘Those lines are a nightmare. I’ve been telling Doctor Argon, but nobody wants to spend money on maintenance when there are fancy company cars to be bought.’

Merv was not waffling for the fun of it; he was waiting for the soluble pad of sedative he had pressed on to Grub’s wrist to take effect.

‘Tell me about it,’ said Grub, suddenly blinking a lot more than he generally did.

‘I’ve been lobbying for new lockers at Police Plaza…I’m really thirsty. Is anyone else thirsty?’ Grub stiffened, frozen by the serum that was spreading through his system. The LEP officer would snap out of it in under two minutes, and be instantly alert. He would have no memory of his unconsciousness, and hopefully he would not notice the time-lapse.

‘Go,’ said Scant tersely.

Merv was already gone. With practised ease, he punched Doctor Argon’s code into Opal’s door. He completed this action faster than Argon ever could, due to hours spent practising on a stolen pad in his apartment. Argon’s code changed every week, but the Brill brothers made certain that they were cleaning outside the room when Argon was on his rounds. The pixies generally had the complete code by midweek.

The battery-powered pad light winked green, and the door slid back. Opal Koboi swung gently before him, suspended in her harness like a bug in an exotic cocoon.

Merv winched her down on to the trolley. Moving briskly and with practised precision, he rolled up Opal’s sleeve and located the scar in her upper arm where the seeker-sleeper had been inserted. He gripped the hard lump between his thumb and forefinger.