One of the more tedious jobs is fixing the sensor buoy network; they mostly repair themselves, but occasionally they get hit by a piece of débris too substantial for them to shrug off.

Gretton supervises an EVA to bring the buoy into the hangar bay; the damage is pretty obvious. PO Gillies supervises the initial assessment; there seems to be an extra box inside the fairly simple casing. It looks mostly like the others, but it seems to be sitting on the data bus between the sensors and the management computer. Gretton suggests launching a replacement buoy (which is checked, and doesn’t have an extra box); this is done. The ship starts to move to the nearest other buoy.

The logs indicate that this buoy hasn’t been touched for several years. Gillies checks for explosives and such like, with passive sensors first. Gretton interrogates it through the standard control interface, with Neilsen running up a highly efficient test suite; it doesn’t react in any way differently from the reference specification.

The next step, which takes longer, is to feed a variety of data through the sensor bus, and see what comes out differently. The box is passing sensor data through unaltered (with a very slight lag).

Taking the box apart shows no sign of manufacture; it might have been done with nanotech assemblers. There’s no obvious anti-tamper. Gillies and Neilsen eventually come up with a particular combination of target profile and signal intensity that doesn’t get passed through. It’s not an exact match to anything in Jane’s; several of the juniors think it’s not entirely unlike the Prizrak stealth corvette. They can’t make out much in the way of details.

Looking at the next buoy, which hasn’t been damaged, there’s no obvious sign of tampering. Neilsen sees some scuff marks consistent with a very low-velocity collision. Gretton checks the logs and finds sightings of something that might be the tampering vehicle, but it’s a very weak signal, that’s been rejected as simply noise. Anything producing that little signal is clearly not a manned vessel. The threshold can be lowered, though of course it’ll mean a lot more false alarms.

Looking at the scatter of signals (over the last few years) that might be intrusions, there’s no particular correlation with specific ships or classes passing through the system. Cross-checking those signals against each other, Findlay and Morrish think that this can’t have been a single drone.

Gretton tries to rig up an isotope analysis of one of the boxes. The results are inconclusive, but he thinks the materials weren’t made in any of the nearby systems.

Some time later, once more of the buoys have been replaced, one of them reports the distinctive pattern near the fourth planet – one which is uninhabitable and not of particular interest. Javelin proceeds in that direction, in a reasonably casual manner with Morrish at the helm, as if to conduct a planetary survey. There’s a very faint trace of an extremely stealthy spacecraft; as Javelin passes into extreme weapons range, the captain calls action stations, but without active sensors.

The target, on the planet’s moon, goes active with targeting sensors. Morrish on helm goes evasive, Findlay gets a solid sensor lock (about a thousand tons, accelerating at about one gravity, consistent with a Prizrak), and Old Nick orders a long-range missile launch. The target doesn’t have a defence ring, the missile detonates, and the enemy ship comes apart.

Javelin closes cautiously, finding a lot of X-ray laser missiles in the débris field. Morrish and Gretton think that the main difference from a standard Prizrak is that some of the missile turrets have been removed in favour of a larger sensor suite. There are two survivors to be picked up, who claim to be merchant spacers pressed by pirates (this is blatantly untrue given the quality of the ship and equipment). A Marine boarding party finds little intelligence information aboard the wreckage, and there’s clearly been some effort made to ensure that, though the dead can be recovered and checked for identifying DNA.

The motivation for this mission is unclear: getting a good look at the base would obviously be useful. This isn’t an especially valuable system, though the outer asteroid belt is mineral-rich. Had it not been for the débris collision, this might have been undetected for a long time.

The sensor buoys are modified to make them more resistant to tampering. There’s some consideration of further actions, and Javelin spends time in-system searching for more concealed ships, without success. There is much writing of reports.

A crew of asteroid miners come back from the outer system after a multi-year stint. Some of them claim to have seen a “weird ship”, a “black moth blocking out the stars”, though the one video is unconvincing at best.

With the anniversary of settlement coming up, the local government is sponsoring a round-the-world air race in solar-powered planes, and the XO hints that it would be really nice to get a team together.

Keene takes charge, with Marine Jones as backup pilot, and McRobert and Entwhistle for mechanical support and navigation.

Javelin will be in orbit, barring emergencies, with a ship’s boat on call for any rescues.

Gretton and McRobert swap out the standard power cells for some spare high-grade laser capacitors; this should allow faster flight during the night segments. Gretton also works on an improved low-friction coating for the skin, and McRobert swaps in skis rather than wheeled landing gear to save weight. Jones spends the pre-race time in the simulator, getting the hang on this particular aircraft.

The other teams are a construction crew, a mining group, some tourists (“I had my legs removed to save weight”), and some remarkably well-disciplined Novaya Europan civilians whom everyone is looking at a bit sideways.

Given the day length, it makes sense to split the run into ten eight-hour shifts, alternating day and night. Keene does a fairly poor job, though the conditions aren’t difficult so he doesn’t lose much time. One of the engines is running a little hot, and Entwhistle has no joy fixing it on the move. The Novaya Europans are talking about “food poisoning”, and their flying is somewhat erratic. Into the first night, the construction crew are pulling ahead with surprising speed, though they’re assessed a time penalty when it turns out that friends in orbit are shining a maser on their solar panels. McRobert sets up the night-time speed and configuration to leave a moderate margin on the power cells. There’s a thunderstorm below as the third shift starts, and Keene continues to do a poor job of flying. The miners have extended their tail boom while in flight. Keene slows down and shuts down the troublesome engine, and Entwhistle’s able to fix it up; Jones makes better time during the night. The tourists are making decent time, though veering quite a bit off their planned course. As dawn breaks, the miners report an engine problem, and end up making a forced landing on the south polar cap; Morrish dispatches a ship’s boat to pick them up. Keene’s starting to do a little better, though still not managing well; he’s not helped by sun-glare off an ice sheet. Jones makes better speed that night, and Keene continues in darkness as they cross the pole. Some interesting high-altitude winds cause minor troubles, but Entwhistle and Jones are able to plot a course to take advantage of them. The tourists are starting to fall behind.

The Novaya Europans are just about in sight at sunset; they bank suddenly as something flashes past them, looking remarkably like a missile. Javelin reports that it seemed to come from the surface; there’s nothing obvious at the launch site, but the XO despatches a boat full of Marines. There’s nothing to see apart from a basic launcher frame; judging by the lack of tracks nearby, it might have been air-dropped.

Keene’s next night shift goes better than before, and McRobert starts thinking about ways of dropping the power cells at the end of the final dark section. This needs collusion from Javelin’s chief engineer, who is persuaded to write them off as “past their service life”. Right now it looks as if this should allow a win, as long as nobody else comes up with anything hugely clever. Jones gets some useful extra lift from a new volcano near the equator. On the final night shift, the Novaya Europans develop a power leak, perhaps from the near miss earlier, and land just barely on shore.

For the last leg, Entwhistle cuts the power cells loose, and Jones holds the aircraft more or less balanced while weight is shifted to compensate. The construction crew do their best to make up time, dumping cells but losing aerodynamic stability, but McRobert pushes extra power to the engines and the Navy comes in ahead by a nose (at least once the time penalty is taken into account). The tourists are well behind, but they don’t seem to mind.