Going under - Justina Robson

Book three of the Quantum Gravity Series sees Lila Black back from her adventures in Demonia and struggling to cope with the even stranger world of Faerie.

And these Faeries couldn't be less like Tinkerbell. These Faeries are capricious, unknowable and dangerous. And they will be Lila's toughest test yet.

Lila may have reached some sort of peace over the fate of her parents, she may have built some bridges with her sister but when you're half cyborg, when you contain enough high-tech weaponry to win a small war, when you don't know your heart, still love an elf and don't trust your bosses you can be capricious unknowable and quiter dangerous enough yourself.

This is a fast moving SF fantasy full of thrills and adventures but informed with a ready wit and prepared to touch on serious themes of identity, reality and sexual politics.