Mark Wahlberg, Tyrese Gibson, Andre Benjamin and Garrett Hedlund star as four adopted brothers out to avenge their mother’s death in Four Brothers.

Bad news for Outkast fans: It could be forever ever, ever ever, before the dynamic duo of Southern rap releases another album. It seems André 3000 has been bitten by the acting bug, and the wound isn’t likely to heal any time in the near future.

No one is quite sure whether it was his performance as Possum Jenkins, Johnny Vulture, Benjamin André, Dookie or all three of the Love Haters in the “Hey Ya” video that did it, but some Hollywood suit must have sat up and taken notice that this one-man band could be the next big thing on the silver screen.

Mr. 3000 (real name: André Benjamin, not Bernie Mac), fresh off a scene-stealing turn in the otherwise grotesquely unfunny Be Cool, has five — count ’em, five — films coming out in the next calendar year (one of them also starring Outkast’s other half, Big Boi as well).

Although the charismatic and thoroughly likeable Benjamin may be a Hollywood natural, it’s the rest of his newest movie, the armor-piercing vendetta flick Four Brothers, that smells like poo poo poo.

As exciting as it may sound, the opening to the film is duller than watching blood dry. An elderly woman and a shopkeeper are gunned down late at night in a convenience store by two masked hoodlums. Her four adopted sons reunite at her home for the funeral while Lt. Green (a gritty Terrence Howard, Crash) gives his partner a convenient description of the Mercer boys, clearly for the audience’s benefit.

All four brothers are easily characterized. There’s the family man, Jeremiah (Benjamin), the ladies’ man, Angel (Tyrese Gibson, 2 Fast 2 Furious), the musician, Jack (Garrett Hedlund, Friday Night Lights), and, for lack of a better term, the hardhead, Bobby (the seriously swollen Mark Wahlberg, The Italian Job).

The lads traipse through the underbelly of Detroit on a mission to find their mother’s killers and execute them. Lucky for us, there’s more than a few money-hungry delinquents behind the murder. A vast criminal empire, payoffs and corrupt cops mean only one thing: Marky Mark and the boys get to kill a whole bunch of people instead of just two.

File Four Brothers in your mind’s so-implausible-it’s-hilarious category. This film is riddled with more question marks than the SATs, and trying to answer them all would give an aspirin a headache.

In one scene, Bobby wants answers, so he storms into a gym full of people watching a basketball game, brandishes a gun and starts asking questions. The funny thing is, if you look in the background, the extras in the scene don’t even appear panicked — they simply give him the “Oh no you didn’t” look and continue chatting.

In another scene, Lt. Green finds a corrupt cop, beats him with a pool cue, takes his gun and badge and starts walking away to his car for no reason whatsoever, only to be shot in the chest when — surprise! — the culprit has a second gun in his belt.

The movie also goes way over the top at times. Idiotic dialogue such as, “Angel, stick that cannon out the window and bust some shells,” and, “It’s maximum ugly,” wouldn’t have even made it on 21 Jump Street.

I’m surprised anybody can live in Detroit with half the politicians and police force on the take and the other half inept. The way director John Singleton paints it, Detroit makes Compton look like downtown Bethesda.

The biggest laugh of the movie, the real anvil that crushes the coyote, comes at the end when a drawn-out fist fight between Bobby and chief baddie Victor Sweet (Chiwetel Ejiofor, Melinda and Melinda) takes place seemingly in the middle of Antarctica (really on top of a frozen Great Lake). Ejiofor fails miserably, again no thanks to second-rate dialogue, in his best attempt at a Denzel-style “King Kong ain’t got nothin’ on me” speech after his character realizes he’s been beaten.

Four Brothers is dumb fun with guns. If you can shut your brain off when you watch, you might have a good time. But if you can’t stop wrapping your brain around the many plot snags and dumb one-liners, you’ll be pulling your chest hair out by the end.

Grade: C+