When streetwise Molly Templar witnesses a brutal murder at the brothel she has recently been apprenticed to, her first instinct is to run back to the poorhouse where she grew up.

But there she finds her fellow orphans butchered, and it slowly dawns on her that she was the real target of the attack.

But when he is framed for his only relative's murder, he is forced to flee for his life, accompanied by an agent of the mysterious Court of the Air.

Chased across the country, Oliver finds himself in the company of thieves, outlaws, and spies, and gradually learns more about the secret that has blighted his life.

Soon Molly and Oliver will find themselves battling a grave threat to civilization, an ancient power thought to have been quelled millennia ago.