Middle of Nowhere, the involving sophomore feature from writer/director Ava DuVernay, is about two kinds of hard time.

While her husband, Derek (Omari Hardwick), is behind bars for a felony, Ruby (Emayatzy Corinealdi) has remanded herself to a kind of emotional solitary confinement. Like Penelope in The Odyssey, she's a lady-in-waiting for a husband to return home. Living on memories of the past and dreams of the future, Ruby - a nurse who, to be available for visits to prison, has deferred her admission to medical school - is absent in the present.

In this film, hushed as a whisper, throbbing with longing, and anchored by Corinealdi's stunning performance, Ruby goes from one who waits to one who acts.

Gorgeously shot by Bradford Young, who sees amethyst undertones everywhere, the film follows Ruby on her various rounds. She ministers to her patients, to Derek, to her sister and nephew. She's there for everyone but herself.

Those closest to Ruby (her bitter mother and bittersweet sister, wonderfully played by Lorraine Toussaint and Edwina Findley) are deeply critical of her unflagging commitment to Derek. This only increases her sense of isolation.

Then Brian (David Oyelowo), the bus driver who ferries her every morning after her night shift, gallantly shows his interest. After she pushes him away, Ruby gets to wondering along the lines of whether fidelity to self trumps spousal fidelity.

Did I say how moving Corinealdi is? As Ruby, she walks as though heavily armored, but with vulnerable eyes. It's the eyes that draw Brian in. Likewise the audience.

In the hands of another filmmaker, this would be a melodrama of a woman who can't be with the one she loves and is tempted by the one she's with. Or the socially engaged story of men in prison and women maintaining the community. But DuVernay, a low-key director sparing in her use of emotion and music, has made an existential drama that is European in its feel.

By this I mean it doesn't have an American film's need to neatly resolve the conflicts and uncertainties. Nor does it have a need to indicate whether characters are good and bad. They just are. DuVernay has made an American art film, a journey into the dark night of the soul that ends in an iridescent dawn. By movie's end, Ruby has shed the emotional armor, walks with grace, and is fully present. Like its central character, Middle of Nowhere is a gem.EndText