Gilbert and Sullivan change the characters, which Sullivan found artificial and lacking in "human interest and probability", as well as being too similar to their earlier opera, "The Sorcerer". As dramatised in the film "Topsy-Turvy", the author and composer were at an impasse until 8 May 1884, when Gilbert dropped the lozenge idea and agreed to provide a libretto without any supernatural elements. The story focuses on a "cheap tailor," Ko-Ko, who is promoted to the position of Lord High Executioner of the town of Titipu. Ko-Ko loves his ward, Yum-Yum, but she loves a musician, who is really the son of the
Crime and Punishment to coerce him to confess. The novel is divided into six parts, with an epilogue. The notion of "intrinsic duality" in "Crime and Punishment" has been commented upon, with the suggestion that there is a degree of symmetry to the book. Edward Wasiolek who has argued that Dostoevsky was a skilled craftsman, highly conscious of the formal pattern in his art, has likened the structure of "Crime and Punishment" to a "flattened X", saying: This compositional balance is achieved by means of the symmetrical distribution of certain key episodes throughout the novel's six parts. The recurrence of these episodes in