The film begins on location in Vietnam, where a film crew is shooting a climactic scene in a movie based on a book about a heroic rescue mission during the war. Robert Downey Jr.’s character has undergone surgery to darken his skin for his role as a black Army sergeant. Ben Stiller plays a former action star who, after playing the role of a retarded boy in his last film, faces the possibility of career death. And Jack Black is an overweight junky who makes bank on fart jokes. The producer (a foul-mouthed, balding Tom Cruise) hates the way the film is coming along, so the director decides to try things guerilla-style. He drops the actors in the middle of the jungle with a map and cue cards, rigs up some cameras in the trees, and lets his special-effects guy have free reign with the explosives. The plot, while funny at times, is utterly predictable, though there are a few surprises along the way. Oddly enough, it’s the actors who make it both predictable and surprising. Stiller and Black play their usual on-screen personas, while Downey Jr. and Cruise throw us for a bit of a loop—even if that loop is a bit over-the-top.