Stross' latest work takes a bit of a step from his usual hi-SF prose, and moves over to the fantasy genre. Stross has taken a dollop of Zelanzy and a pinch of Beam Piper, to create a fantasy world that's not exactly like anything you'll have ever read before.
The protagonist - a thirty something reporter - finds that she can walk between worlds; our modern world of the 2000's and another, nearly identical world, that is still ruled by a feudal system and is technologically stunted. Soon she finds that she is the classical long lost family member, of a family that is anything but loving and more reminiscent of a world domineering mafia.