‘I took the liberty of bringing the security bot with us,’ Zaquil told Ysbel and Goodwill. ‘It is over the camp now. There is a rudimentary electrical system, but no power is being drawn and I haven’t spotted any inhabitants.’

‘Perhaps they ran away when they saw our sky boat,’ Goodwill said. ‘Perhaps they are hiding in the forest.’

‘They would not have had time to run very far,’ Zaquil said. ‘And the security bot is equipped with infrared, microwave and ultrasonic sensors.’

‘My people are good at hiding,’ Goodwill said stubbornly.

‘We need to take a look,’ Ysbel said.

‘I will keep watch, ready to intervene in the unlikely event you walk into trouble. We can stay in touch via your bot,’ Zaquil said, and the little machine dropped out of the air and settled on Ysbel’s arm with the dainty precision of a dragonfly.

‘Don’t do anything unless I tell you,’ Ysbel said.

‘Even if you appear to be in immediate danger?’

‘If I am, I’ll yell.’

Cool air, the clean scent of pine trees. Running water murmuring to itself. Birdsong. Sunlight slanting low and golden; shadows deep and dark under the trees. The hopper had left Concord a little after midnight and it was late in the evening here, an hour or so before sunset and the brief night of boreal summer.

Ysbel and Goodwill hiked through pine trees and sparse undergrowth to a broad stretch of grass and dirt and a double-wire fence at the boundary of the big square clearing. Two deer standing hock-high in tawny grass turned one after the other and bounded away, white rumps flashing, and disappeared into the dark beneath the trees.

They followed the fence and found a pair of sliding gates. The outer gate was shut but unlocked, and took a little muscle to push open because weeds had choked its rollers; the inner gate stood open. The row of burrows, their mouths stoppered with rammed earth, the turf humped over them brown and withered, were enclosed by a secondary fence topped with razor wire, and the small grid of rectangular concrete foundations of cabins or huts stood close by in a square of weedy compacted dirt. It seemed that both natives and humans had been living there, but who had been the guards and who had been the inmates?

Strip fields gone to weeds stretched towards the far side of the clearing, their boundaries marked by ditches and gravel paths, and the vanes of a windpump turned uncertainly in the soft breeze. As they approached it, Goodwill pointed out a patch of a rambling groundvine, the good-for-all plant whose roots were commonly used by natives to make tea. There were orphan sweetroot and starchroot plants amongst the grass and weeds, too.