[movieperson id="438080"]Zac Efron[/movieperson] is at his most personable in [movie id="365329"]"17 Again."[/movie] With his insinuating eyebrows, carefree hair and light comic touch, he's a fresh, sensitive hunk for the teen-rom-com moment. Unfortunately, the movie provides him with no rom in which to show his stuff -- or with much of anything else, either. He wanders through the film in search of a well-turned line or an irresistibly clever situation and arrives at the end empty-handed.

The picture begins in 1989, with Efron's character, Mike O'Donnell, a high-school basketball star, turning his back on a college sports scholarship in order to marry his girlfriend, Scarlet (Allison Miller). Flash forward 20 years and Mike has matured, rather unpersuasively, into Matthew Perry. This older Mike is not a happy guy. Scarlet (now played by Leslie Mann) is divorcing him; their two kids, Alex (Sterling Knight) and Maggie ([movieperson id="183179"]Michelle Trachtenberg[/movieperson]), can't be bothered concealing their contempt for him; and he's just been passed over for a job promotion. If only he could return to his high-school glory days and choose a different path.

We've been here before, in the company of many a better body-swap movie ("Big," "Vice Versa," etc.). The body-swap concept is simple, but this picture fumbles it. The older Mike does get turned back into his 17-year-old self (in the most witless way -- by a twinkly, Santa-like janitor, played by Brian Doyle-Murray, who could be a refugee from a road-show version of "Miracle on 34th Street"). But he doesn't get sent back to 1989 -- he remains in the here-and-now. (So much for relocating that old path.) Thus, when he manages to enroll in high school again, his kids, Alex and Maggie, are among his fellow students. Will Alex introduce young Mike to his mom, the still-grown-up Scarlet? Will these two feel the tug of attraction across their age gap? Will Maggie start coming on to the hot new guy in school? Will things get a little icky?

Efron is somewhat at sea in all of this because there's no satisfying love story in which his character can take part. We understand that the older Mike (about whose presumable disappearance no one seems to wonder) is inhabiting young Mike's body, and that he longs to reconcile with Scarlet. But there's no way for Efron's young Mike to really act on these feelings for the older woman without crossing the PG-13 barrier into a whole different kind of movie. And since making a play for any of the high-school girls on hand would be similarly creepy, given the story's premise, Efron is effectively neutered as a romantic lead.

The only actual canoodling in the film occurs in a silly comic subplot involving Mike's old high-school buddy Ned (Thomas Lennon), a sword-and-sorcery geek who's grown up into a sword-and-sorcery geek with money. It's Ned who gets young Mike into high school by posing as his father; and it's at the school where Ned meets and is immediately smitten by the principal, Jane Masterson (Melora Hardin). They are, of course, an impossible pair. Jane seems to be a no-nonsense educrat, while Ned -- whose home is a fantasy bog of comic books, Tolkien tomes and vintage light sabers -- might have beamed in from another galaxy. Lennon chews the scenery with alarming relish; but when his Ned looks at Jane in a tender moment and expresses his feelings in flawless fantasy-speak -- I'll say no more -- and she replies in kind, we sigh with relief: not only because we've been dying for something snappy to happen (this is the picture's one inspired moment), but because it looks like somebody in this oddly under-heated production is finally going to score.

Check out everything we've got on "17 Again."

Don't miss Kurt Loder's review of "State of Play," also new in theaters this week.

For breaking news, celebrity columns, humor and more -- updated around the clock -- visit MTVMoviesBlog.com.