These days, very few books keep me up until 2 at night. This one did it for me.
In a fantasy city inspired by Venice in the Renaissance, Locke Lamora is a thief. Not any common thief though, he's been brought up to be the BEST thief, along with his crew. He made me think of Arsène Lupin or Fantômas (minus the sadistic approach—which is taken by Lamora's enemies).
The action is fast-paced, the world is well made, but I regret that almost all major characters are men.