There's a story about the suggested sequel to the gladiator that has Maximus traveling through fucking time. The reason that movie was pitched was because the director and the writer specifically did not want to make that movie. But the contract for the Gladiator required a multiple movie deal if it was successful. So they pitched the craziest shit imaginable and the studio let them out of the contact.
A lot of movies are made this away. Original IP doesn't get picked up unless a studio thinks they can milk it.