In her third film as director, Sarah Polley turns a documentary eye on her own family, drawing out an entertaining and intriguing tale of the way in which families convert their experiences, both happy and painful, into a shared history. Focusing on discoveries about the life of the director’s mother — actress Diane Polley, who died in 1987 — the film pieces together conflicting details and perspectives from her siblings, her father, and her mother’s friends.

Some unexpected revelations lend real drama to this exercise, but what keeps us fully engaged is the natural storytelling ability of the Polley family. Ultimately, the interviewees’ amusing awareness that they are contributing to an unavoidably distorting storytelling process elevates the film above TV shows like Who Do You Think You Are?, in which our basic fascination with family history is mined in a more straightforward, but much less satisfying way.