Through a series of freak occurrences, a group of actors shooting a big-budget war movie are forced to become the soldiers they are portraying. Black will play Jeff "Fats" Portnoy, an overweight gross-out comedian, who's forced to kick his drug addiction while filming on location in the jungle. Downey Jr. will play Kirk Lazarus, the greatest actor of his generation and a four-time Oscar winner. Baruchel will play Kevin Sandusky, an unknown actor on the set and Stiller plays Speedman.