"At World's End" was meant to return it tonally to a character piece. Sparrow, in particular, is tinged with madness after extended solitary confinement in Davy Jones's Locker, and now desires immortality. Sparrow struggles with what it takes to be a moral person, after his honest streak caused his doom in the second film. This is mainly shown by his increasingly erratic behaviour and Jack's hallucinations, which appeared to be simply his deranged mind in the beginning where dozens of "Jack Sparrows" appeared to crew the ship in his solitary exile, but later the hallucinations grew more important and there were mainly two "Jacks" constantly arguing about which path to follow: the immortality or the mortality. The last hallucination took place while Jack was imprisoned on the Dutchman, where his honest streak won. By the end of "At World's End", Sparrow is sailing to the Fountain of Youth, an early concept for the second film. Rossio said in 2007 that a fourth film was possible, and producer Jerry Bruckheimer expressed interest in a spin-off. Gore Verbinski concurred that "all of the stories set in motion by the first film have been resolved. If there ever were another "Pirates of the Caribbean" film, I would start fresh and focus on the further adventures of Captain Jack Sparrow."