Meanwhile the team’s been shopping for high-energy food, clothing, hexamine fuel, binoculars, and survival gear in general – as well as less usual supplies, such as parachutes and silk scarves as low-bulk trade goods.

Jagdeep flies them to Kathmandu, and for the next few days sneaks them over the border into Tibet; they search from the air for anything out of place. David writes software for his deck to point out anything that isn’t snow, rock or cloud; after a bit he adds exceptions for villages, yaks, and Chinese J-7 (MiG-21) fighter patrols. Jagdeep favours a ground-hugging flying style, and they don’t seem to get spotted.

It’s on the south face of a mountain shown on the charts as Makan-la that they see something odd: a ledge that’s curiously clear of snow, with odd lines forming patterns in the rock. Round the other side on the north face is a cloud that stays in place, not moving with the wind. The ledge is easily large enough to land on, and as they approach the lines seem to form the shape of a symbolic bird.

The team spreads out and examines the rock face to the side, looking for entrances. There are two low rises, one at each end of the “landing strip”, which seem as though they’d be a plausible way to start moving round the mountain, but no caves or anything like that. By each rise is a small slit trench that’s clearly been carved.

Jagdeep calls from the plane that there’s a cloud half a mile away which isn’t behaving like a cloud: it’s making about twenty knots against the wind. The group unloads survival gear from the plane, and tell Jagdeep to take off and come back in an hour or so. As he makes his takeoff run, the cloud disperses, revealing a Nile Empire airship; six Paket fighters drop free, two of them going after Jagdeep, the other four swooping over the plateau.

Everyone scrambles for the trench as the Pakets come in for strafing runs. The cover is hard, and the fighters don’t have much luck scoring hits. Stephen, Diamond and Thorfin all open fire (Thorfin’s crossbow bolt doesn’t do much damage, but it’s surely disconcerting); as his cockpit glass crazes, the first pilot breaks off and heads back to the airship. As the planes come round for another pass, they do the same thing again: this time Stephen gets several more hits, and Diamond aims for the under-armoured fuel tanks. The combination of damage and distraction spooks the pilot, and he loses control, swooping low over the trench to plunge into a snow bank and explode. That’s enough for the remaining two, who head back to the airship. David intercepts radio transmissions: a female voice, calling them fools and weaklings, and ordering the shocktroopers to be sent in.

(Somewhere off in the distance there’s the sound of an explosion. The team assumes that this is one of the Pakets sent after Jagdeep.)

The team takes advantage of the distraction to get away, moving up the rise and along what seems to be a rough path round the side of the mountain. It’s a mixture of walk, scramble and climb, and it’s hard going, with crevasses hidden under the snow, temperatures well below freezing, and icy winds.

Along the way they encounter a large, white-furred anthropoid ape, which has apparently just killed some smaller animal; when they stop and look, it retreats. There’s also a substantial cliff breaking the trail, though with Diamond’s flight and Stephen’s and Thorfin’s climbing skills it’s not a major obstacle. They spend the night in tents, not warm but not perilously cold either, with sleep disturbed by the occasional screams of plummeting shocktroopers, and move on the next day.

They’ve been gradually ascending, and finally approach the cloud-bank. Close up it looks even more unnatural: it billows slowly as clouds do, but there’s a clear edge to it, overhanging the top of a rough and boulder-strewn slope. Diamond flies up to look; as she sticks her head through, everything becomes much warmer. Inside the cloud bank is a ruined stone city, mixed with lush vegetation. There’s no sign of snow on the ground.

The rest of the team heads up the slope and through the cloud layer into the city… and that’s when the ambush is sprung.