Complete Unknown is a dreary movie built on an irresistible idea. It features a beautiful protagonist who literally reinvents herself every year or so, bouncing from city to city, changing her name and background, learning new trades, and breaking off relationships before they get serious. She is an intriguing, complex person, but what makes her fascinating is what makes the movie fail: We can’t invest in a character who isn’t invested in herself.

Rachel Weisz plays “Alice,” previously known as Consuelo and Jennifer. Early on, she makes eyes at a sweet, portly economic analyst in a New York cafeteria, which gets her invited to his best friend’s birthday party. She knows what she’s doing. The friend is Tom (Michael Shannon), who immediately recognizes her as the girl who got away. Tom has an identity crisis of his own; his wife has been accepted to graduate school in California, but he isn’t sure if he wants to tag along. So when his disappearing high school sweetheart shows up at his house with a different name, a great new look, and an offer to school him in the art of personal re-invention, it’s something like a cosmic coincidence. Or maybe just shoddy screenwriting.

Director Joshua Marston (Maria Full of Grace) films these early scenes with a clear sense of purpose. His characters often hide in the corners of the frame, with negative space dominating their view. It highlights their disconnectedness, emptiness, and mutually self-destructive focus on what’s absent from their lives. Like everything else about the film, it’s a choice that is more interesting than effective. It’s mysterious and beguiling, yes, but the film doesn’t have a story in its pocket—nor the character development or point-of-view—to pay it off.

When Tom and Alice reunite, Complete Unknown seems to click into place, and the negative space disappears. Alice flees the party, and Tom follows into her world, ready to embrace her way of invented life. A friendly senior citizen (Kathy Bates, in her element) injures herself on the street, and they pose as doctors, and follow her home to offer her treatment. In the comfort of the apartment she shares with her Haitian husband (a sparkling Danny Glover), Tom exercises his muscles of re-invention, with both his future and his past (which, Alice shows, is always subject to revision) in the balance.

The actors are well-cast, but the script simply gives them too big a hill to climb. Weisz ably hints at a river of pain underneath her icy hot exterior, but the parameters of her character require her to remain frustratingly out of reach. We never like her because we never know her. Meanwhile, Shannon is always watchable, but his character is too passive to be compelling. Tom can’t decide whether to stay with his uncommonly attractive girlfriend, and when he abandons her that night to follow Alice, he can’t even bring himself to feel liberated by his decision. She lives in the moment, but he’s just a tourist there, which means neither can carry a compelling emotional arc.

Maybe Complete Unknown would have worked better as a comedy. You know, one of those ‘80s movies in which a buttoned-up urbanite learns to let loose with the help of a free-spirited dream girl. All the elements are there: An awkward domestic situation, an escalating series of lies, and a potentially wild, rambunctious night in the city. To turn this into compelling drama is an ambitious undertaking. At the very least, you’d need an artist with a penetrating understanding of his characters and what drives them, and Complete Unknown just doesn’t have that. Just like its protagonist, the film seems to have forgotten what it is, or it never knew in the first place. 

Complete Unknown opens today at Bethesda Row.