The movie splashes memories into the present to illustrate the stickiness of the past. The technique of intercutting past and present is risky, and it can easily feel contrived and ham-fisted. But here, thanks in part to the stellar editing of Ronald Sanders (David Cronenberg’s editor), the technique enhances the story Mortensen’s getting at. (Cronenberg, a friend and past collaborator of Mortensen’s, has a welcome, winking cameo as a proctologist.)