The last steep ridge of the Shatterlands looms ahead, swaddled in cloud. Even the auxiliary engines have come on stream now, bellowing with the effort as they help to heave the city up this final slope. On the edge of Base Tier, snow blows in between the tier supports, melting as it settles on the warm iron pavements. Airdock Green Police Station is quiet tonight, but then most nights are quiet at Airdock Green. Sometimes there’s a drunk from the pubs on Crumb Street to deal with, sometimes a pickpocket works the crowds of engine labourers around the elevator station on payday, but by and large there’s not much crime down here on Base Tier. It was different in the days when the Airdocks were busy, but there’s a smart new air-harbour on Tier Four now where most of the traffic pulls in. The coppers up there must see some cases, Sergeant Anders thinks wistfully as he strolls towards Airdock Green to start his shift. Stolen airships, smugglers, brawls. . . The quays behind his little station are half abandoned, except for some Goshawk 51s which the Guild of Engineers keeps moored there, their plump white envelopes like the speech bubbles of cartoon characters with nothing left to say.