Elite con artists calling themselves the "Gentleman Bastards" rob the rich of the city of Camorr, based on late medieval Venice but on an unnamed world.

Through a series of confidence tricks on the rich, they defy the Secret Peace, an unspoken agreement between the criminal underground and the Duke's government which allows for the existence of organized crime with the understanding that the peerage and the servants of justice are off limits.

After Chains' death, Locke becomes garrista of the group, consisting of Jean Tannen, an expert fighter; Calo and Galdo Sanza, jack-of-all-trades identical twins; Bug, a young apprentice; and Sabetha, a master charmer who resides elsewhere during the events of the novel.

Secretly, the Bastards have actually been using elaborate schemes to swindle various nobles out of large sums, and have amassed a considerable fortune; they purchase the trinkets they pass on to Barsavi as tribute, in accordance with their small-time reputation.

Jean and Bug save him, but they realize that the Gray King has double-crossed them; they return to their secret lair and find their wealth stolen and the Sanza twins brutally murdered.

Meanwhile, Jean investigates the after-dark activity of Raza's minions and realizes that the new Capa is secretly loading his newfound wealth onto a ship supposedly quarantined for plague.

Wary of revenge by other Bondsmages should he be killed, Jean and Locke remove his fingers and tongue so he cannot gesture or speak spells, leaving him alive but insane.

To destroy the peers, he gives the Duke of Camorr four sculptures, actually time bombs filled with a substance that will cause all of the nobles and their children present at the celebration to slide into permanent mindlessness.

When no treasure is found on the barge, Vorchenza realizes that the Thorn tricked her into destroying the ship filled with Raza's fortune, which is now an offering to the god of thieves for Locke's murdered friends.