Instead of car chases and explosions, they are assigned to the boring task of bicycle duty at a local park. When they get noticed for fouling up a major drug bust, they are reassigned to a long-dormant program the department is looking to revive called 21 Jump Street, in which youthful cops are placed undercover in high schools to stamp out criminal activity involving teenagers. Overseen by the always-angry Captain Dickson (ICE CUBE), their first assignment is to bust up a new drug ring possibly being run by the ambitious senior Eric Molson (DAVE FRANCO).

Schmidt and Jenko are forced to deal with the emotional ramifications of suddenly being back at high school. When they accidentally mix up their covers, Schmidt falls in with the popular crowd and becomes a favorite of drama teacher Mr. Gordon (CHRIS PARNELL) and track coach Mr. Walters (ROB RIGGLE). Even a pretty drama student named Molly (BRIE LARSON) becomes attracted to him. Jenko, meanwhile, is embraced by the honor roll students and has to fend off the sexual advances of Ms. Griggs (ELLIE KEMPER), his AP Chemistry teacher -- all while trying to bust the drug ring.

Jenko is one of those guys who may have peaked back in his teen years. So, when the two rookie cops are assigned to infiltrate a high school drug ring, they not only have to bring about a bust...but they also have to deal with their own feelings about being back in the land of cliques, pop quizzes, and prom dates.

This plot description makes the film sound like a thoughtful, even serious endeavor. And, it's true that some care has been taken here with the characters and their feelings and motivations. The flick, though, also contains loads of bad language, drug references, dope-dealing students and faculty, alcohol served to minors by adults, smutty sex talk, and bloody gunplay. And while that was basically my high school experience in a nutshell, I concede that for anyone who either grew up with the original "21 Jump Street" on TV or remember it in reruns, you might be taken aback by the truly hard "R" the cast and crew go for here.

But you know what? The sweet and the sour work together this time. The balance is spot on. Hill and Tatum have great chemistry, and you do accept Schmidt and Jenko as real characters - it's actually one of the better buddy cop movies to hit screens since that genre's 1980s heyday. At the same time, if you like raunchy, profane humor, there are some belly laughs to be had here.

The film's laughs are not confined to just the smutty kind either. Its best moments are where the characters step out of the film's story and comment on either 1) the film itself or 2) cop-movie clichés, in general. There's a great bit early on where Jenko and Schmidt's police commander tells them they are being reassigned to "Jump Street." When they ask what the program is, he goes on this rant about it being a "recycled idea from the 1980s" that the bosses are trying to pass off as "something new and innovative," but is really just further proof of a system that is quickly running out of ideas. Of course, he's also talking about Hollywood. That guy, along with Ice Cube's Captain Dickson, then have great fun dressing down both Hill and Tatum for their shortcomings as actors and the clichéd characters they are playing. And the two guys just sit there and take it. It's beautiful.

Later during a freeway car chase, there is another great bit about the various characters bracing for gigantic Hollywood pyrotechnic fireballs that never seem to come. When a film has this much fun laughing at itself and its participants, the sense of play is infectious. And for anyone wondering if a certain actor from the original "21 Jump Street" days makes a cameo, he does (and he's not alone). It's one of the smartest uses of a cameo appearance I've seen since Shirley MacLaine popped up in the Past Lives Pavilion of "Defending Your Life" 20 years ago. Even the late "21 Jump Street" series creator Stephen J. Cannell is worked into the film ever so briefly in a clever way.

Eventually, the film does run out of comic steam. But I'd say for 90 percent of its running time, the action and the comedy mix hums along at a terrific pace. This is a real surprise. I give it a very entertaining 7.5 out of 10. (T. Durgin)