Joseph Gordon-Levitt joins 'Inception'

Joseph Gordon-Levitt is coming on board Christopher Nolan's "Inception," the filmmaker's thriller for Warner Bros. that stars Leonardo DiCaprio.

A veil of secrecy exists over loglines, though the project, which Nolan also wrote, is described as a contemporary sci-fi actioner set within "the architecture of the mind."

It is known that Gordon-Levitt is taking the role to have been played by James Franco, who bowed out over scheduling issues. He would play an associate of DiCaprio's character, a CEO-type.

Marion Cotillard is already on board as DiCaprio's wife, while Ellen Page is playing a grad student and DiCaprio's sidekick. Cillian Murphy is also in the cast.

Nolan and the studio are aiming for a summer shoot ahead of a 2010 release.

Nolan and Emma Thomas are producing through their Warners-based Syncopy Films shingle.

Gordon-Levitt, repped by CAA, has a big summer lined up: He stars in "500 Days of Summer," the romantic comedy that earned much buzz in Sundance and is now set for a July 17 release by Fox Searchlight, and plays the villainous Cobra Commander in Paramount tentpole "G. I. Joe: The Rise of Cobra," which opens Aug. 7.