The casting process for Danny Boyle‘s Trance has been a Rube Goldberg-style puzzle that, frankly, doesn’t make sense. Michael Fassbender was reported as starring in the lead role, but we then heard that his X-Men: First Class co-star, James McAvoy, was taking that role. And then he… wasn’t. After this little misunderstanding, Fassbender left due to scheduling issues, and Colin Firth was then mentioned as taking his part. The King’s Speech Oscar winner soon dropped it, and Vincent Cassel was then rumored to take this twice-abandoned role. Scarlett Johansson has even been mentioned as the female lead, Elizabeth, but that may have just changed.

Are you still with me?

Deadline now informs us that Rosario Dawson and Cassel are about to sign on to the thriller, which has previously been described as having the “dark, sexy, hard-edged tone of Boyle films like Shallow Grave and Trainspotting.” Dawson will play the woman who gets into “an unusual relationship” with two thieves; it isn’t clear if this is the same role that Johansson was mentioned for, but it seems pretty likely. Cassel is playing the accomplice to an art heist, a character who McAvoy “runs afoul of.” Produced by Christian Colson, the story follows said art heist, which must be completed through unconventional methods when something goes wrong; the film is also a remake of Joe Ahearne‘s 2001 British TV movie. You can read a synopsis of the story below:

An assistant at an auction house masterminds the heist and teams up with a gang of thieves, but suffers a blow to the head and wakes up with amnesia. He is the only one who knows where the painting’s location is and after his continued failure to remember, the gang begins to suspect duplicity on his part and hire a female hypnotist to get into his brain.

The development schedule on this movie pretty unique — the shoot is happening this fall, and then Boyle will go and work on the opening ceremony of the 2012 Olympics. Once that’s completed, he’ll edit the picture, with the movie seeing a release from Fox Searchlight in March 2013. I don’t know if this will affect how the final product comes out — I certainly hope not, because this sounds very appealing to me — but no matter what, it should be interesting to speculate when it hits theaters. Let’s focus on the movie’s quality first and foremost, of course, but there should definitely be some kind of impact, for better or for worse.

Are you looking forward to this film, and do these additions change your expectations at all? Can you figure out the casting process for this movie?