'Are you sure about this, Cille? There's nothing on the map.'

'Ja. The archives say there was a shelter here, back in 2100. The satellite pics confirm it. Here, pull over.'

Ernst directed their vehicle to stop, and turned his chair around to face his colleague. 'Show me,' he ordered.

Cille unrolled her digital tableau and spread it across both their laps. The screen faded in gently, showing a live map of their surroundings, with their current location superimposed as a bright wireframe. Updated by digital feeds from their vehicle, the neon-edged avatar parked in the shadow of a miniature dust-dune. Historical data and satellite footage overlaid the landscape in hard-edged blue and orange, respectively.

'This whole area used to be forest, before the war,' she explained.

Ernst grunted. 'Which one?'

'The last one, kvajpande.' She rolled her eyes. 'Never mind. Here, these are the plans we found for the shelter. We extrapolated the possible locations for the ventilation systems, and from that we plotted the rest of the layout, and the entrance should be around here. It would have been concealed deep within the forest, but now there is no forest.'

'Thanks to the French.'

'Nobody ever proved the Biovore came from France,' she chided.

'Except they were working on nano-disassemblers, and then this happened, and then suddenly they denied all knowledge,' insisted Ernst. 'It was either an experiment, or an accident, and our own government was in on it! Everybody knows it.'

'They were not. I wish you'd stop. This is why we're out here, scrabbling for ruins instead of in the city earning a nice salary and living in a house that isn't on wheels.'

'Whatever. The satellite has found the entrance? Show me.'

The map understood his words, and pinged a circle around the region that most likely represented the entrance to an underground shelter.

Ernst frowned, turning the facts over in his head. He was a slow thinker, slow but deep.

'Why would anybody put a shelter this far away from the population? Who was it supposed to protect?'

'I don't know. Maybe it was privately built, for some company executives?'

'You should check those plans again. I don't think this will be a shelter. I think this will be a bunker.'

Cille shrugged. 'Even better. So long as there's something of value down there, we're good.'

'As you say. Dispatch drones one directly to site entrance.' This last was enunciated in the careful tone of voice everybody learned to use when speaking to computers. 'Drone two will remain at one hundred metres altitude.'

A portion of the windscreen lit up with two video feeds as the survey drones, old models cobbled together from salvaged parts, flitted through the air toward their designated waypoints.

'Proceed toward objective,' commanded Ernst, and the lumbering six-wheeler rumbled into motion.

On-screen, the first drone had arrived at the expected location of the entrance, and was slowly panning around. The second drone, high above, provided a wide-angle view of the location, marking drone one on the picture with a stylised eyeball icon.

Ernst looked out of the window, preferring to keep an eye on their home's progress rather than let the computer drive unsupervised through rough terrain. 'Well?' he asked. 'Have they found it?'

'There is a... mound. I expect the entrance has been buried.'

'It probably caved in. We'll get closer and use the excavator.'

'About that. We, ah, we don't really have permission to excavate the site.'

'Too bad. If it's lost, then it doesn't belong to anybody. Finders keepers.'

She flashed a grin. 'I hoped you'd see it that way.'

Cille set the drones to carry out more detailed mapping, feeding back to her map while Ernst drew up an excavation plan on his own console. Before long they stood before the mound, ready to break earth.

Both wore aug-vision goggles and haptic rigs. Ernst twitched a command to the crawler's computer and a pair of articulated limbs unfolded from a hatch at the rear. The thicker of the two limbs was a broad grasping scoop, while the other had a modular head, able to switch between a jackhammer, borer, or chainsaw blade. None of the heads were selected at present.

Both limbs were bedecked with cameras, which fed into the controllers' goggles as a single 3D composite. The prospecting rig also included enhanced imaging, to detect weak spots and objects of unusual density.

Ernst grunted. Sure enough, there was a heavy hatch beneath about a metre of earth. He fed his requirements into the computer and set it to work clearing away the bulk.

'Did you find the ventilation shafts?' he asked. 'Is it worth sending in one of the probes for a look?'

Cille shook her head. 'I found the locations, but the intakes are buried.'

'We'll have to wear the haz-rigs when we go in, then. The ventilators will have been choked with earth decades ago.'

'It's not earth,' she pointed out. 'It's layers of compacted ash. This is what the Biovore did to the forest.'

'Ugh. Tell me no more. Make sure the suits are ready, and prep one of the robots for biohazard testing. I don't want to get dissolved, or turned into stone or something.'

Cille rolled her eyes. 'Yes dear.'

Ernst turned his attention back to the work at hand. The bulk of the ash had been cleared away, and now he supervised the finer work of exposing the armoured entryway. Fortunately the soft ash was biologically inert and contained no plants, so it cleared away quickly and easily, almost like sand. It was a task of mere minutes to completely excavate the entrance door.

The biovore weapon had eaten the paint from the door, as well as the computerised access controls. Ernst gave the melted wiring a disparaging look, then casually smashed the door in with the excavator. The hatchway buckled, but held.

Cille laughed, and flashed a portion of the blueprints to his goggles. 'The door looks nice and strong, yes.'

'Yes, yes, I get your point.' He sighed, and extended the crawler's second limb. He activated the jackhammer and dug in through the entryway's tunnel wall, bypassing the armoured door completely.

This was considerably slower going, but he soon had a two-metre hole into the underground complex. Cille strode over to the hole, safely sealed in her triple-layered exploration suit. A small wheeled robot trundled along at her heel, awaiting the order to go inside.

'There's another hatch inside. An airlock. It's on the plans. It's not armoured like the outer door, I should be able to force it.'

Ernst nodded. Fed by the crawler's enhanced cameras he could see the inner door quite clearly. Cille's suit had amplified night-vision, protective plating and a lightweight exoskeleton. He watched as she clomped in through the hole he'd made and planted herself firmly in front of the doorway. Her arms twitched as she activated the exo-frame's motors, extending the spikes and setting them into between the door and frame.

She heaved, and the door shifted in its track. Dust fell, the sheet metal buckled a little, and then something gave way with a snap and the door opened a hand's-breadth. She looked back over her shoulder, as best she could in the bulky suit. Her voice came through over Ernst's radio, clear and triumphant.

'Access granted.'

Chapters...