The One I Love begins with a familiar enough premise before thankfully veering wildly into murky waters. Sophie and Ethan's marriage is in trouble—we can tell because we first meet them in marriage counseling, looking straight ahead instead of at each other. They cling to memories of an idealized past, and while they're both determined to mend the marriage, they can't seem to agree on how to get there. Their knowing therapist (Ted Danson) goes to a secret drawer and pulls out just the thing to get this couple back on track: A brochure offering a seemingly ordinary weekend retreat to a secluded vacation home. This place has saved countless marriages from ruins, the therapist assures them.

Before long, the couple discovers there's a guesthouse on the property, and here the film delves into the world of magical realism, the particulars of which I have taken great pains to obscure from you in this review. Just trust me that what happens in the guesthouse represents a thought experiment ripe with possibility, wherein the characters are given an opportunity to explore the nature of who they truly are and what they want from each other.

Your ability to root for Sophie and Ethan will depend on how cynical you've become about relationships. At 32, I've still never had a relationship last longer than a couple of years, so the idea of marriage remains for me a hazy unknown. These days it seems like you can't get away from the barrage of books, movies and television shows warning us of how difficult and fraught a marriage is. "Don't think it's going to be easy forever!" everyone seems to be saying at every moment. Okay, okay, we get it.

The film stars Elisabeth Moss ("Mad Men," "Top of the Lake") and Mark Duplass ("The League," Your Sister's Sister and Safety Not Guaranteed) as the couple who may or may not be falling out of love for good. Apart from Danson's brief but necessary role as gatekeeper to the new reality, they are really the only actors in play, so we need to at least believe in, if not root for them. Both actors get the job done, particularly Moss, who has a way of wearing the moment on her face with such plaintive sincerity you want to let her get away with almost anything.

Director Charlie McDowell achieved notoriety a few years ago with a Twitter account called "Dear Girls Above Me," in which he shares snippets of conversation overheard from two vapid women in the floor above him and the lessons learned. The Twitter account was adapted to a book and now at 31, he makes his directoral debut with The One I Love. Remember the name, because I'm guessing we'll be seeing a lot more from him in the future.

These are just the kind of films we need—the kind that are driven not by production values but by characters and ideas. Justin Lader's script takes the impossible premise to strange and unexpected corners. It's always fun to see how characters will react when confronted with a game-changing new reality. They under-react just a little, in my opinion, but then, we can't have an entire film with the characters huddling in the corner shaking and crying. We have to accept that they have accepted what's happened and let them fully explore the new reality with seasoned astonishment. At 91 minutes, The One I Love is a thoroughly enjoyable, sometimes comedic and at times surprisingly dark romp through a troubled marriage. Watch helplessly as they make the wrong choices, betray their promises and confront their true selves.

A final warning: Unless you're in the mood for uncomfortable looks or a long boring talk about your relationship to follow, this is one of those movies you might want to leave your date at home for and instead see alone or with friends.

The One I Love continues at the Wilma.