The cast for director Christopher Nolan’s newest film, Inception, is coming together. Having already cast Leonardo Dicaprio in the lead role, Nolan has added Joseph Gordon-Levitt to the mix. Gordon-Levitt is best known for his role on the television series 3rd Rock from the Sun, as well as movies like Stop Loss and this summer’s G.I Joe: Rise of Cobra. Gordon-Levitt, along with Leo Dicaprio, will join actors Ellen Page (Juno) and Cillian Murphy (Batman Begins) in a movie being deemed, “contemporary sci-fi action set within the architecture of the mind.” THR is reporting Gordon-Levitt picked up this part after James Franco dropped out of the project due to scheduling conflicts. Inception is due to arrive in theaters July 16, 2010.