— So would your friend in Deilte have known of your death?

I didn’t.

· Perhaps, perhaps not. He is an antiquarian data-collector like myself, but a recluse. He may have heard through mutual acquaintances.

· Right, Fassin sent. — So I must make for Deilte. What was your friend’s name?

· Chimilinith.

The name was barely out of Valseir’s signal pit when Fassin registered a neutrino burst.

· Any particular part of Deilte? he asked, starting to look round in more detail.

· Chimilinith tended to move his house around. But I imagine the locals will know of him.

· Okay. So, did you take a look at this data? What did it look like?

The diamond-bubble private box was nearly empty: just the two of them, the float-tray and bowl — he’d scanned them automatically when he’d entered and they were just what they appeared to be, no more — and the screens, which also seemed perfectly standard. Who’d be using neutrino comms? From where? Why the sudden burst, just then?

— It looked like algebra.

Fassin scanned Valseir’s simple clothes. No hint of anything high-tech there. The most sophisticated thing in his robes was the weave itself.

— Algebra? he asked.

There was nothing on the inside or the outside surface of the diamond bubble itself. He scanned the access tube. Clear.

— It looked like alien algebra, Valseir told him.

Fassin looked up at the undersurface of the Blimper immediately above, then swept for anything in the clear gas space outside within the same radius. Still nothing. Something further outside, then.

— Alien? he asked, distracted.

There seemed to be nothing nearby. There was the Dzunda, then nothing for a hundred metres or so until the next Blimper, then the other spectator and ancillary craft beyond — with the single accompanying Dreadnought Puisiel a few klicks further up in the atmosphere, easily keeping pace with the spectating fleet — then the GasClippers themselves, currently starting to round the Storm Wall buoy which marked this short race’s first turning point.

· Alien symbology. Though not entirely. I thought I recognised some of the symbols. They looked like a form of Translatory IV, a pan-species type, so-called “universal’ notation dating from perhaps two billion years ago, invented by the Wopuld — long extinct invert spongiforms — though with elements of ancient Dweller icons. I would have made notes, but I thought better of committing any of it to a form I could carry around save what exists — necessarily sketchy — in my own mind. Hence I have not been able to work on it since.

Fassin was taking in what was being said — and recording it on the gascraft’s systems in case he wanted to review it later -but he was still frantically scanning the volume all around them for some form of bug or surveillance device. Another burst of what certainly seemed like neutrino comms registered on the little gascraft’s sensors; a sudden pattern in the general wash of near-massless particle chaos.

The first burst had come immediately Valseir had spoken the name of the Dweller he’d given the folder to. Could it really just have been coincidence? But how could anybody have overheard? They were communicating by whisper signal, coherent light beams flickering from one surface-sunk transceiver pit to another. There was no way to intercept what they were saying unless someone dropped a mirror or some sensor into the beams.

Could it be him? Had the gascraft itself been bugged? Had Hatherence put something on him? He scanned and system-checked, finding nothing.

The Blimper above them ascended quickly and steadily as the GasClippers roared up the sheer face of the storm. The Dzunda rose into direct sunlight.

— So, just a field of equations ? Fassin asked the old Dweller.

The drug-fume haze in the private box was suddenly lit up, resolving into tiny individual particles of vapour, a tiny fraction of them glinting and glittering.

— Possibly just the one long one.

Horrified, Fassin sucked a little of the surrounding vapour into the arrowhead’s high-res analysis unit.

— One piece of algebra? he asked.

The results coming from the gascraft’s high-tech nose looked bizarre, surface receptors seeming to change their mind about what they were smelling. Fassin toggled the analysis down another level of detail to electron microscopy.

— Possibly, Valseir replied.

Outside, towards the Storm Wall, a few tens of metres away, something showed, briefly caught in the slanting sunlight and taking just an instant too long to adapt to the new lighting conditions.

The results from the arrowhead’s internal electron microscope were for a moment baffling. Then Fassin realised what his analysis unit was looking at. Nanotech. A thin soup of tiny machines, receptors, analysers, processors and signallers, small enough to be suspended in the atmosphere, light enough to float in the midst of the drug smoke like particles of the fumes themselves. That was how they’d been bugged. There was something in the gas between them, riding right in the middle of their signal beams and capable of picking up their meaning. Nothing as gross as a mirror or some photon microphone dangling from a wire, just this, just these, just stuff that was supposed to be banned.

— Valseir, he sent urgently. — Who brought this drug bowl in here?

He turned up visual magnification, staring hard at the point in the open gas outside, where something had shown in the sunlight an instant before. There. He up-magged again, almost to the point of graininess.

— What? Valseir said, sounding confused. — Well, it was here when I -

A rough sphere, forty metres away, barely ten centimetres across, almost perfectly camouflaged, like a disc of clear glass in front of the real view. Hint of a comms pit, a tiny crater-like dish, pointing right at them. Fassin swung round to put himself between the tiny, distant machine and the old Dweller, then went right up to him, comms pit to comms pit like amorous Dwellers kiss-signalling.

Valseir tried to rote back. — What the — ?

· We’ve been bugged, Valseir, Fassin sent. — Watched, listened to. The bowl smoke is part nanotech. We need to get out, now.

· What? But -

Another burst of neutrino comms. Now that he knew where to look, it was definitely coming from the camouflaged sphere outside.

— Out, Valseir. Now.

And another burst. This time from above. High above. Valseir pushed Fassin away. — The bowl smoke… ?

— Get out! Fassin sent, pushing the old Dweller towards the access port in the top of the diamond bubble box.

Outside, the little sphere was rushing towards them. Fassin got underneath Valseir and forced him upwards.

— Fassin! All right! Valseir started to rise under his own power, entering the vertical access tube. The little sphere burst through the diamond bubble, shards spraying. It came to a stop just inside the jagged hole, still disguised, just a blur in the air.

“Major Taak!” it shouted. “This is General Linosu of the Shrievalty Ocula. This device is under the control of the Nasqueron Expeditionary Force. Don’t be alarmed. We’re coming down to—”

The voice cut off as the little sphere was pierced by a hair-thin line of cerise light. The noise resounded, sharp and sudden, round the diamond bubble enclosure. Debris flew from the tiny machine, rattling against the far side of the private box. Fassin whirled to see Hatherence dropping down round the side of the Dzunda, carapace silvered. The laser beam had come from her. The little spherical device dropped its disguise, revealing itself as a mirror-finish machine with stubby wings. It had a tiny hole in one flank, a much larger one on the far side, producing smoke. It rolled over in the air, made a crackling noise, then dropped to the transparent floor. Above him, Fassin was aware of Valseir hesitating in the access tube. Slipstream wind whistled in through the hole in the diamond bubble.