Reilly plays John, who has set about embodying the term "sad-sack" following his divorce from Jamie (Catherine Keener). When we first meet him, she has shown up to insist he climb out of his self-imposed solitary confinement and come to her engagement party, which he does with all the excitement and good humor of a death row inmate. After a few hours of excruciating awkwardness, he encounters Molly (Marisa Tomei), who is attracted to his tragicomic depression, and the two make tentative plans to start seeing each other. Unfortunately for John, Molly has a slightly bizarre secret: her twentysomething son Cyrus, who appears friendly but may or may not be hiding deep-seated contempt for John and a weird obsession with his mother right beneath the surface.

If it sounds a little like Reilly's Ferrell comedy Step Brothers, it kinda is and kinda isn't, existing in a void between the two styles. There are moments in Cyrus that are pure goofiness, and yet the whole thing feels realistic in the same low-key, minimalist way Baghead does. Whether or not this mixture is entirely the Duplass' doing or whether some of it might have been studio-imposed is hard to say, but turth be told, the mixture is a little rockier than I expected.

The film lives and dies on the strengths of its cast, which runs the gamut of possibilities. Tomei is perfect, finding a balance between the sweet, sexy woman who is believable both as someone who would want to be with Reilly and someone who the audience can like, and the slightly damaged person who would blind herself to her son's various methods of two-facedness and manipulation. Reilly, then, lands in the middle, giving a performance that I appreciated more as the movie continued and the actor moved from drunken wackiness to almost purely dramatic acting. Sadly, Hill seems a little miscast in the title role, able to nail the man-boy and awkward aspects of the role, but not quite the emotional and psychological complexity the third act asks of him.

Cyrus isn't quite the rousing experience I was hoping for from the crossover between arthouse and frathouse (maybe the Duplass brothers' next project, Jeff Who Lives at Home, starring Jason Segel, will be that movie), but it's a small-scale success that's at least worth a look. There's a few complex characters, a few good performances, and a single, pivotal moment in which a character says what's on everyone's mind that no studio comedy would ever allow, and it's one of the biggest, most cathartic laughs of the year.