People like mystery stories because of the satisfaction of solving one. Looking for clues, sizing up characters, watching a film competitively; all require active participation from an audience. Source Code, the second feature-length film from Director Duncan Jones, is emblematic of this, with a meandering plot that misleads as often as it reveals. Assuming the pieces are all in place, this is a thoroughly engaging experience, and leads to the cryptic praise of satisfied watchers who want to tell you everything but simply can’t reveal anything, lest the enumerable unveilings be ruined. Despite the film’s shifting moods, Jones has put together a lively action film that serves double-time as an exhausting mind puzzle.