Tonight's episode is a mini-preview of another action movie: James Cameron's Avatar. While actor Stephen Lang has been acting since the early 1980s, in films like Manhunter, Tombstone and Gods and Generals, he's about to play his most high-profile role ever, as the scarred Col. Quaritch in Cameron's highly anticipated 3-D epic. Tonight, he'll guest-star on Psych, when a cop bar is shot up during Officer McNab's birthday party, and the target appears to be Detective Lassiter. Who would want to kill Lassiter? We have no idea, but if you're really curious, we recommend using the "biggest guest actor on a show is the perp" theory, which was probably also the case when Lang guested on multiple Law & Orders.

Psych airs tonight at 10/9C on USA, where character actors are welcome. For more suggestions, we recommend our Week in Preview.