In an interview, Director Sarah Polley said that Seth Rogen and Michelle Williams brought their characters to life in unexpected ways. Trust her, she means it. They play a married couple, Lou and Margot, whose relationship is tested when Margot finds herself attracted to their new neighbor, Daniel (played by newcomer Luke Kirby). There seems to be no artifice in the actors’ performances; it’s as if we’re peeking through a window and observing a doomed relationship, up close, as Margot experiences lust and temptation for the first time. The actors’ work is appealing and beautifully nuanced; this applies to the supporting cast as well, which includes Sarah Silverman as a recovering alcoholic. The pinpoint precision of their work, in just a handful of scenes, achieves more than most actors can with reams of dialogue (let’s say “Twilight for instance).”Take This Waltz” may seem like a depressing movie to watch, and perhaps it is. But director Polley, whose previous work was the unforgettable “Away from Her” gives us a movie that explores a relationship in an honest and poignant way. It would be hard to discuss it without revealing major plot points so I’ll just leave it at that. Just know that you won’t be able to get it out of your head.