From his office on the Street of the Assassins, Nathan Sutherland, English Honorary Consul to Venice, assists unfortunate tourists as best he can. A steady but unexciting life that dramatically changes when he is offered a large sum of money to look after a small package containing a prayer book illustrated by the Venetian master Giovanni Bellini. Unknown to Nathan, from a palazzo on the Grand Canal twin brothers Domenico and Arcangelo Moro, motivated by nothing more than mutual hatred, have been playing out a complex game of art theft for 20 years. And now Nathan finds himself unwittingly drawn into their deadly business.