STORIES WE TELL Her next subject: YOU! (Quick, be more interesting.)

SARAH POLLEY IS AMAZING, to such a degree that she is even kind of suspect. Careful and serious, she seems like a much older person trapped in a 34-year-old body. Who else would make their directorial feature debut Away from Her, a devastating Alzheimer's drama? With Stories We Tell, she takes on the art of documentary—and not only makes something human and impactful, but folds the genre in on itself.

Ostensibly, Stories is a study of Polley's family, centered on her mother Diane, who died of cancer when Polley was 11. With almost cold calculation, Polley puts virtually everyone in her family—siblings, father, aunts, family friends—into the hot seat and tasks them with telling "the whole story": what Diane was like, what her relationship with her father was like, and far into the plot-thickening beyond.

In part an examination of memory and storytelling, Polley's editing choices are particularly great, using the standard talking-head format to illustrative and often comedic effect. Spliced throughout are Super 8 home videos that go a long way toward making Diane a compelling, if ephemeral, subject. The dreamlike fuzziness of those images contrasts with the matter-of-fact present-day scenes, where we see Polley setting up shots, asking questions, slouching around in jeans and socks.

The film undergoes a series of revelations as it slowly becomes apparent not only what the project is about, but what it is, which is a complicated, thought-provoking thing. The film's final minutes rush at you with a little too much eagerness to dissect its own significance, perhaps, and for such a personal subject, Polley retains her distance. But what we're left with is an extraordinary intellectual investigation delivered more deftly than most directors twice her age are capable of.