On Screen reviews the new comedy "Step Brothers," an Adam McKay film starring comedy duo Will Ferrell and John C. Reilly.

    “Step Brothers” opens with something outrageous, at least in a modern comedy, a whirlwind romance between sixty-somethings, including a roll in a hotel bed. From there the film is a hit and miss proposition and it’s mostly downhill.

    In short order Dr. Robert Doback (Richard Jenkins) and Nancy Huff (Mary Steenburgen) head for the altar and move in together. The wrinkle is that each has a 40ish son still living at home. Robert’s son Dale (John C. Reilly) is a college dropout with plans to go into the family business. Nancy’s boy Brennan (Will Ferrell) just lost his job at Petsmart and still suffers from a talent show trauma inflicted by younger brother Derrick.

    While Robert and Nancy are both successful professionals and quickly settle into their new marriage, Dale and Brennan are at each other’s throats from the get go. Dale makes the mistake of declaring his drum set off limits. Brennan, naturally, defiles the drums the first chance he gets. Body parts are involved.

    Naturally the reason the two boys don’t get along is that they’re just alike. They have the bodies of adults but the life experience and maturity of 12-year-olds. They wear tuxes to the job interviews Richard sets up for them. When told they’re old enough to make their own decisions they can’t seem to comprehend what that means.

    Eventually Brennan and Dale come to an understanding, primarily due to their mutual hate of Derrick (Adam Scott). If possible, they’re more dangerous as friends than they were as enemies.

    Both Ferrell and Reilly are revisiting familiar territory in “Step Brothers,” co-written by Ferrell and Adam McKay (“Talladega Nights,” “Anchorman”). Once again they’re playing childlike adults with no sense of what normal people do. This gives them the freedom to be outrageous but it also seems to limit the humor to a very juvenile style.

    Where the still-very sharp “South Park” uses children to tackle adult material, Ferrell and McKay use adult language to tell fart jokes. It’s juvenile humor for adults. Jokes that involve actual brain cells are pretty rare, lines such as “Your voice is a combination of Fergie and Jesus” are about as smart as it gets.

    Story-wise, “Step Brothers” wanders a lot on its way to a point. It feels long at just 95 minutes due to side stories about playground intimidation and Derrick’s wife’s affair with Dale. Meanwhile, after introducing Robert’s blind neighbor in a way that seems to set something up, the character is never seen again.

    The boys’ efforts to keep the house from being sold are both funny and inventive. There should have been more, but like a distracted child the film moves on to less amusing material such as sleepwalking at Christmas.

    Both Reilly and Ferrell have proved they are capable of much, much more. Diehard fans will probably enjoy “Step Brothers” but the rest of us will have to wait for these two to grow up a bit more. Rated R for strong language, crude content. √1/2