The Nightbound Land, book 1: Roil
Trent Jamieson2011

Shale is in trouble - the creature-filled darkness known as the Roil is expanding, consuming the land, swallowing cities whole. Where once there were 12 metropolises, now only 4 remain.

It's up to a drug addict, an old man and a woman bent on revenge to try to save their city - and the world.