From the back of the book:
Seattle is a fractured city, split between history and modernity. The Unchained can stumble through rifts in time and space and wind up decades in the past. Why? Some failed experiment of the God-Machine? A side effect of human ingenuity? Or are the splinter timelines in the City of Flowers a deliberate design, leading up to something greater still?
Splintered City: Seattle includes more detail on the alternate timelines described in Demon: the Descent, as well as a host of story hooks and characters for use in your chronicle. Also presented are brief suggestions on what Seattle might hold for the other denizens of the World of Darkness.