An intriguing documentary about twin brothers, amnesia and a filmmaker functioning as a therapist of last resort.

While it's hard to do complete justice to their heartbreaking tale involving a dark, traumatic childhood, Perkins deserves all the credit for treating it with the respect and care that it deserves.

It's tragic but utterly compelling viewing as director Ed Perkins allows the two men to share their stories -- and their lifelong anguish -- direct to camera before they sit down face-to-face for a final, painful catharsis.

Perkins slowly builds the tension by structuring each of the first two acts around the individual brothers. That sets up a heart-shattering third act that brings every raw feeling and deeply rooted emotion to the surface.