Too often seen slumming it in wisecracking, big-lug roles, Dwayne Johnson (2012's "Journey 2: The Mysterious Island") puts on his serious face for "Snitch," a crime drama out to highlight the hypocrisies and gross lack of logic in federal mandatory sentences. In a justice system where the punishment doesn't always match the crime, 18-year-old Jason Collins (Rafi Gavron) is arrested for drug possession with intent to sell when a friend insists on mailing him a large stash of ecstasy pills to temporarily hold onto. Once the package is opened and the tracker goes off, Jason is caught, suddenly facing a minimum of ten years behind bars unless he is willing to implicate others as drug dealers. Since he isn't a part of that world, he genuinely doesn't know of anyone—unless, that is, he's willing to falsely accuse, which he's not. Desperate to save his son, John Matthews (Dwayne Johnson) pleads with District Attorney Joanne Keeghan (Susan Sarandon) for another option, and she begrudgingly gives him one: if he can go undercover within a U.S. drug cartel branch and deliver dealers to her, she will set him free.

Inspired by a true story but nevertheless stretching the boundaries of plausibility for dramatic purposes, "Snitch" grabs one's attention very quickly, the film jumping directly into its heightened conflict. Feeling abandoned by his father when John and first wife Sylvie (Melina Kanakaredes) divorced and she received custody, Jason has grown resentful as he's watched his dad move into a big house, remarry, and seemingly replace him with a daughter. Not bringing Jason with him was out of John's hands, but he understands his son's misgivings and subsequent rebellion, and wants nothing more than to make it up to him. Thus, writer-director Ric Roman Waugh and co-writer Justin Haythe (2008's "Revolutionary Road") position "Snitch" as a father-son tale interspersed with the heightened stakes of the underworld of narcotics trading and selling. Aided by an ex-con employee, Daniel James (Jon Bernthal), who wants to go straight for his own family but cannot turn down a promised $20,000 payday, John sets his sights first on Malik (Michael K. Williams). One false move, however, could tip off the cartel headed by Juan Carlos 'El Topo' Pintera (Benjamin Bratt), and if that happens they're as good as dead.

"Snitch" plays like a narrow, more streamlined, less complex variation on 2000's Steven Soderbergh opus "Traffic," further homogenized by an insistent PG-13 rating that renders its violent climactic showdowns bland and spineless. The plot, which is not without its useful intentions, requires a tougher treatment of the material than this film is willing to tackle. Where things go is easily guessed—save for the dearth of action, which only comes into play during a forced third-act highway chase—while overwrought repetition sets in as John's and Daniel's dips into dangerous activity lead to both their respective wives—Analisa (Nadine Velasquez) and Vanessa (Lela Loren)—tearfully harping on them. These scenes play like bad soap operas, and they're not helped by the knowledge that all of the most thankless parts have been given to the females in the cast, who are on hand to either provide exposition or whine and yell at the men in their lives.

Ably headlining the picture is Dwayne Johnson, for the first time in quite a while asked to really act rather than just bulge his glistening biceps and spit out one-liners. Despite his daunting physical presence, Johnson has a gift of still being able to play a sympathetic everyman—albeit one who can probably take care of himself, thank you very much. There's no time for humor in this project—its grave solemnity almost becomes too much in the second half, sucking the baser entertainment value from its proceedings—but Johnson is affecting all the same as he vows to come through for a son whose face gets more swollen and beat up every time John visits him. As Daniel, Jon Bernthal (2010's "The Ghost Writer") is eye-catching portraying a man whose seen the inside of a prison cell twice before and doesn't want to let down his wife and impressionable young son again. Susan Sarandon (2012's "Jeff, Who Lives at Home") continues her reign as Hollywood's most graceful, virtually ageless beauty, even here, where she is mostly asked to sit behind a desk and toss out advice, as D.A. Joanne Keeghan. And then there's Barry Pepper (2013's "Broken City"), whose Federal Agent Cooper is overshadowed completely by a hideous Fu Manchu beard.

"You're the one teaching me what real character and integrity is all about," John tells his prison-jumpsuited son, who has decided he'd rather be locked up for ten to thirty years than point the finger at one of his friends or acquaintances in exchange for a lighter sentence. "Snitch" isn't the most elegant of dramas when it comes to people opening up their mouths and saying words, and the script's trajectory is so predictable as to be an afterthought. Helmer Ric Roman Waugh's filmmaking isn't wholly inept, however. In only a few shared scenes, the relationship between John and son Jason is heartfelt without becoming mushy, and this helps to inject interest for a while in a familiar premise of a man going undercover in a criminal world he knows little about. This good will can only go so far, and at 112 minutes, it's stretched awfully thin by the contrived, then exceedingly pat, finale. There is little room for denial that "Snitch" means well, but there also isn't anything to give it those extra shots of immediacy, grit and verve it so desperately needs.