The film opens with a carnival in Venice as a prelude to a series of erotic encounters that follow Giacomo Casanova through the cities of 18th-century Europe. The organizers of the festival attempt to raise a gigantic bust (sculpture) from the water; this fails, which is taken as a bad omen. Casanova is then introduced, as he visits one of Venice's islands to copulate with a fake nun for the pleasure of a rich voyeur; Casanova succeeds in entertaining him, but is frustrated that the man finds no interest in his research into alchemy and his further scheming. As he rows back to the mainland, Casanova is arrested, judged and imprisoned by the High Court over his famed debauchery.