Terry Gilliam’s fittingly Quixotic quest to make a movie set against the backdrop of Miguel de Cervantes’ 17th century magnum opus “Don Quixote” may finally be coming to a head.

Empire bumped into the auteur recently at a party in Cannes for the Doha Film Institute, and revealed that Ewan McGregor has joined the cast of “The Man Who Killed Don Quixote.”

McGregor will take over the role for a far-too-busy Johnny Depp in which he will play a 21st century advertising executive who travels back in time to 17th century Spain.  He meets Don Quixote and becomes entangled in his myriad adventures. Robert Duvall will play Quixote, replacing Jean Rochefort.

“Robert Duvall is one of the greats, no question – and he can ride a horse!” laughed Gilliam. “And Ewan has gotten better over the years. He was wonderful in ‘The Ghost.’ There’s a lot of colours to Ewan that he’s not been showing recently and it’s time for him to show them again. He’s got a great sense of humour and he’s a wonderful actor. He’s wonderfully boyish and can be charming – when he flashes a smile, everybody melts. He wields it like a nuclear bomb!”

“Quixote” is a project Gilliam has been struggling to get off the ground for years.  His first attempt to make the film in 2000, with Depp and Rochefort attached, was met with an unthinkable array of misfortune, chronicled in the documentary, “Lost in La Mancha.”

Gilliam also pegged a budget somewhere near the $20 million mark, a significant drop from the $35 million he had for his first attempt in 2000.