Sniper found the hole less than accommodating and had to smash away lumps of coral with his heavy claw before he could follow the little drone through. Once through he too sent beams of light from the projectors on either side of his mouth. The two drones were now in a narrow cavern. At the back of this, a cube-shaped hollow had been cut into the rock, and in it rested three large hammer-whelk shells. Thirteen moved forward until it was hovering over one of these. Its ribbed tail uncoiled, split at the end, and gripped the rim of the shell.

‘I thought you were only intended for observation,’ said Sniper.

‘I am,’ said Thirteen.

‘How did you excavate that?’ Sniper asked, indicating the cavity with his heavy claw.

‘With a boosted geological laser and patience.’

‘And what about your tail? Last I recollect, the Warden didn’t allow you any manipulation of your environment. . . ever since those thrall units . . .’

Thirteen gave an aerial shrug above the whelk shell. ‘If you have the funds, you can buy the alterations. No doubt that is something you’ve been telling Windcheater for some time,’ the little drone replied.

‘I have . . . but does the Warden know about your . . . alterations?’

‘No,’ said Thirteen, ‘nor does he know about these.’ With that, the submind tipped the whelk shell to reveal that it was full of amberclam pearls. Sniper shifted forward in the confined space and turned a palp eye to each of the shells in turn. The second shell was full of short rods of translucent pink stone Sniper recognized as fossilized glister. The third shell contained lumps of greenish rock. Only a laser chromatographic scan rendered the delightful news that this substance was pure green sapphire.

‘Quite a collection,’ said the war drone. ‘What do you intend to do with it?’

‘To buy my laser upgrade I had to stick a pearl to my tail with amberclam glue and transport it over four thousand kilometres. That took me the best part of a solstan year and I lost four pearls in the process. My tail alteration took five years, by the same methods.’

Sniper gave his deadly grin and backed out of the cave. Dropping the whelk shell back into its place, Thirteen followed him out into the emerald day.

‘You still have your account at the Norvabank, then?’ Sniper asked.

‘I do, though there’s not much in it right now.’

Thirteen rose up through the trees at high speed, in an explosion of foliage and leaves. Sniper followed, deliberately going through the thickest branch he could see, just for the hell of it, and smashing it to splinters. Once clear of the dingle the two drones flew out over the bay and settled towards its calm waters.

‘So what sort of percentages are we talking here?’ asked the war drone.