Thoroughly anti-character and anti-epiphany, John Curran's We Don't Live Here Anymore is an intelligent, unfussy, and inconclusive look at martial infidelity.

The film tracks two married couples who are entwined in both in friendship and adultery. Mark Ruffalo plays the lead only in the sense that Curran allows the audience a sentence or two of his inner monologue, which momentarily illuminates his drifting marriage to Laura Dern. Ruffalo is sleeping with his best friend's wife, played by Naomi Watts, while Dern mopes around the house and contemplates the advances of Watts' husband, played by Peter Krause.

Details in the scenario are sparse and more mysterious than illuminating-the status of the two husbands as scruffy, unsatisfied academic professionals; reoccurring mentions of financial woe despite bourgeois lifestyle; unsure levels and directions of love-and Larry Gross' fluid screenplay has little interest in fleshing out the characters or their situation.

As the film winds down the direction Curran and Gross have chosen for their film begs a look for the film's ultimate motive, but the unsettled brooding of the couples, the muted tones of their lives and the coursing, modern score by Michael Convertino lend richly authentic atmosphere in place of a linear end point or concrete conclusion. Curran has an observational lucidity, and it facilitates the uniformly excellent cast who take the well-written but weakly ended script and runs with it.

Mark Ruffalo has picked another solid role in a solid film, and he continues to build a filmography of roles that seem to flow naturally from one to the other, the characters coming directly out the actor instead of functioning as a skin of mannerisms. Naomi Watts is also of particular note, for while many of the other actors successfully inhabit Gross' behavioral script, Watts nearly turns his behaviorism into a character.

Often when Watts is on-screen one gets a picture of what We Don't Live Here Anymore would be if it went in another direction entirely. Likewise, in one sublimely awkward sequence Curran uses the soundtrack expressionistically and out blossoms a moment where technique is utilized to supplement the script by stylistically elaborating on the unspoken tension between the couples. The lack of these things-utilization of cinematic possibilities and a more explanative, psychological character study-is not particularly a flaw, but the impact of Watts' performance and Curran’s one or two forays out of his graceful utilitarian direction illustrate that the film could work as something other than a mannered, effective mood piece.