The inexplicables - Cherie Priest

Adventures await Rector "Wreck 'em" Sherman. About to turn eighteen, he's facing ejection from the orphanage that passed for home. He should also choose a trade, but work is scarce in steam-powered Seattle. And Rector has more unconventional plans.

He's started dealing in sap, a yellow narcotic produced by rebels and outlaws within the city's toxic walled enclave. What's worse, he's been sampling his wares. Other problems include being haunted by an old friend with a grudge. The pressure builds until he sneaks behind the wall himself, seeking both (un)gainful employment and excitement.

As rumoured, he finds a terrifying host of the hungry undead, and then there's the monster. Rector's certain that his attacker wasn't human, or undead. But he's going to need more proof than his own addled word to expose it. His new mission becomes a compulsion when others witness the creature's destructiveness, and give its kind a name. The Inexplicables.

Praise for the series: 'Everything you'd want
pure mad adventure' Cory Doctorow, 'Adventure of rollicking pace and sweeping proportions' Scott Westerfeld, 'Cherie Priest is the high priestess of steampunk' The Seattle Times