Sin is an orphan living in the pseudo-Victorian steampunk city of Coxford. While out picking pockets one day, he becomes the victim of a scam which results in a significant change of fortune. Sin is whisked away to Lenheim Palace - the secret headquarters of COG (Covert Operations Group) to train to be a agent. Sin forms friendships and applies himself to his lessons. But when he stumbles over a piece of information about his own past, Sin begins to think his recruitment to COG hasn't been a happy accident. The more he digs, the more danger he finds himself in ... and he doesn't know who he can trust.