Stories We Tell, the third feature directed by Sarah Polley (Away From Her), takes the proposition that reality is more dramatic than fiction and tests it out in a startlingly original, even head-spinning way. For most of the movie, we're watching a documentary of family secrets made in the dark, confessional, into-the-abyss spirit of Capturing the Friedmans. The film's central figure, though long deceased, is Polley's own mother, Diane, whom we see in Super-8 home-movie footage, and who's described as a free spirit stuck in a life that couldn't contain her. Her marriage to Michael, a dashing actor she met in 1965 when they were in a play together, cools off pretty fast, and both he and Polley's adult siblings speak candidly of Diane's hidden pleasures and torments: the lovers she took, the kids from an earlier marriage she lost custody of.
The film's big revelation (it involves not only Diane but also Sarah Polley herself) has the kick of a mule. Yet while we're marveling at (and perhaps identifying with) the soap opera twists and hidden emotional depths of ''ordinary'' lives, Polley plays a different sort of game, deconstructing the story she's telling or, rather, demonstrating how our memories live on as subjective stories, although the events actually happened. By the end, the rug gets pulled out from under us, showing that even the reality we think we see may be an illusion. A-