He may have been instrumental in getting director Jon Favreau hired on the project, but Robert Downey, Jr., long attached to the high-concept tentpole Cowboys & Aliens, will no longer star in the film.

The issue at hand is one of workload. Between the Iron Man and potential Sherlock Holmes franchises, Downey has a considerable amount to do already, and as the LA Times reports, adding another big film with franchise potential wouldn’t leave room for much of anything else. Dreamworks is still planning to make the film this year — the LAT says ‘tentatively planning,’ which doesn’t inspire optimism — but doing so will obviously be contingent upon finding a lead. The film will feature “outer-space creatures who land in Arizona circa the mid-19th century intent on enslaving the local population — until a group of cowboys and Apache Indians fight back.”

The report suggests that this might be taken as an indicator that another Sherlock Holmes movie is on the fast track at Warner Bros. — so that’s a couple layers of speculation, then? Regardless, expect to hear something about another Holmes movie sooner rather than later.