Iron angel - Alan Campbell

Order has collapsed in Deepgate. The chained city is now in ruins, and the Deadsands beyond are full of fleeing refugees. Meanwhile, the Spine militia is trying to halt the exodus of panicking citizens through brutal force. Rachel and the young angel Dill are dragged off to the Temple torture chambers . . . but strange things start to happen as a foul red mist rises from the abyss beneath the city. For the god Ulcis's death has left the gates to Hell unguarded, and certain forces in the fathomless darkness beneath Deepgate have noticed an opportunity.

Only the offspring of the dread goddess Ayen understand this new danger. Already, Cospinol, god of brine and fog, is coming to save his brother's temple -- and to hunt down Ulcis's murderers. His foul, fog-wreathed skyship has already reached Sandport, bringing along its own version of hell.

By now, Rachel just wants to keep her companion alive. Escaping their prison, and with enemies closing in on all sides, she is forced to undertake a perilous journey across the Deadsands towards the distant land of Pandemeria. But there the battlefield at Coreollis is fated to witness a clash of powers -- a contest between men and gods and archons and slaves, all forced into desperate alliances.