Theories of what’s going on continue to be mulled over. Keane and McRobert consider that whatever’s going on, it must be fairly short-term, because if a base gets destroyed the reasons for building it would still be there. KK and Fenton are more in charge of this analysis than anyone else.

Interrogating the captured SAS researchers has been somewhat helpful; in their universe, their covert operatives did manage to kick off a war between UK and Novaya Europa, their navy managed to take the planet, and they’ve been working on the dig site ever since.

The object has been on the sea bed probably for tens of thousands of years, at the very least. Speculation involves that it’s using humans as tools to get it out of its present situation; and/or that it might have some way of generating jump points.

Meanwhile, Keane has an exciting and challenging duty, mediating between the base and port authorities in a dispute over atmospheric shipping rates. One incident: during one of these meetings, the Spot-fragment in the corner starts picking at the air, finding what proves to be harmless small nanotech particles; very basic ones, with no particular payload. Entwhistle and McRobert hunt around for more of the contamination; Spot is able to provide a gradient, and they track down the highest concentration in the air recycling plant. There’s no obvious source, but that’s where most of it seems to be. It’s definitely human tech, and not tagged, which is a little unusual.

A few days later, there’s a report from downside: automated systems have suddenly started failing in a particular part of town. The local police are treating it as suspicious; Keane sends in Entwhistle and McRobert to liaise with them.

There’s an industrial building which was not yet officially occupied, at the centre of the pattern of failures, that seems to have been cleaned out in a hurry. Judging by what was left behind, someone was building small swarmbots – they’re typically insect down to pinhead size.

Poking about a bit more with sensors reveals some incomplete bots, roughly pinhead sized and inactive. They have wings which ought to be able to move them at a slow walking pace, or against a light breeze, but the payload space is empty. It looks as if it was intended to be something mechanical.

Whoever was using this place did a fairly good job of not leaving a trace. Looking at the broken-down machinery, the common factor is small perforations and patches cut out, often from the inside, and apparently aiming for important components rather than for specific materials; McRobert’s able to find a fair few inactive machines, fitted with blades and drills which seem to have been used to do the damage.

She powers up one of them, and it sends out a repeated radio ping. Firing up a couple more leads to some quick data bursts, after which they all shut down, having apparently burned out their memories.

It’s trickier to read their memories directly, but there does seem to be a slight tropism built in: they’ll be particularly active around a specific chemical mix, which Entwhistle recognise as something you’d find in the UV sterilisation phase of an air recycling plant.

There’s nothing amiss aboard Javelin, but down in the city’s air plant there are rather more microbots; they’re removed, and they haven’t done too much damage yet.

Keene looks into what would happen if the dome’s life support failed: it wouldn’t be an immediate crisis, and there is backup equipment, so while it would be disruptive it wouldn’t be widely fatal.

Keene, Gillies, Entwhistle and McRobert go out in Port Spot with signal analysis kit and jammers, looking for more large masses of the bots, with police backup; they don’t have much success. The size of operation seen earlier would take more than one bedroom, but it could readily fit into a decent-sized house. On the other hand, by now they’re all feeling a bit sensitive to coincidence, so when there’s a complaint to the police by the staff of one of the downport’s fast food places, that their management has apparently vanished, leaving them without feedstock for the food synthesisers and more importantly unpaid, they pay attention. There’s a lot of digging into virtual corporations and disguised ownership, which takes a while; this is particularly tricky because the profits haven’t been taken out, but rather ploughed back into the business. Looking into the food synthesisers reveals many nanobots mixed into the stock, tucked inside plastic coatings that should be resistant to gut pH changes.

There’s a comprehensive search; the bots don’t seem to have reached Javelin, but they’re all over the base. Removing them isn’t a major challenge once it’s known that they’re there.

When the police do eventually track down the fast-food place’s owners, it’s an abandoned flat full of materials in Russian; the consensus is that this is a heavy-handed attempt to implicate Novaya Europa. There’s also a large laser communicator with system-tracking mount, presumably too big to clear out in haste; its memory of target coordinates has been wiped.

There’s some thought about when the bad guys might have found out about the alien site. The team looks through the original survey data from thirty years ago – which are remarkably incomplete, though possibly that’s just the way planetary surveys get done. There was certainly no thought in those days of establishing a naval base here. Looking at the surveyors proves more fruitful: most of them have moved on to other careers, but one in particular, a Peter Mitchell, seems to be living on his own asteroid, somewhere towards the core. Now, that’s not completely implausible for someone who’s been particularly diligent about saving his pay, but there’s nothing else in his record to indicate that.

A Novaya Europan merchant comes through the gate with a cargo of air-recycling machinery, and her captain is rather surprised when it’s pounced on and bought (though thoroughly checked before it’s installed).