No, this PG-rated fantasy adventure is not about a high-school kid fronting a band of misfits for the variety show where he wins a music college scholarship. Someone stole Zeus’s lightning bolt, a less impressive old-school light saber, and Percy Jackson (Logan Lerman) is wrongly fingered. Percy has no idea he’s a demigod, born of mortal Sally Jackson (Catherine Keener) and the full-blooded god Poseidon (Kevin McKidd). “I guess we all got daddy issues,” observes another kid with divinity in his genealogy. Soon our hero is secreted to Camp Half Blood where he meets Athena’s daughter Annabeth (Alexandra Daddario). For extra credit: what kind of kids are born of two demigods? Quarter deities? On what chromosome is the god gene? Percy learns his dyslexia is due to his “hardwired” literacy in Greek. That’s what made English on the chalkboard unreadable: “it’s Greek to him.” His attention disorder is really warrior-grade, battle-ready alertness. Chris Columbus (two “Harry Potter”s and two “Home Alone”s) directs a screenplay that Craig Titley adapted from Rick Riordan’s 2005 book, the first in a series of five by the middle-school teacher. The plot is a cross-country quest by Percy, Annabeth and a sidekick satyr Grover (Brandon T. Jackson) to find three green pearls that serve as “Get-Out-of-Hades” hall passes, so they can rescue Percy’s mom from Hades. Because saving your mom is always more important than averting a multi-god smackdown with the collateral damage of “the end of life as we know it.” To orient viewers who didn’t do their mythology homework, the screen teens cite “High School Musical” and “Extreme Makeover,” and use an iPod in a way Apple never anticipated. This places us life as we know it. Slightly inventive are updates for the Land of the Lotus-eaters and the “H” sign pointing to hell. Best line: “Hi, mom.” With Pierce Brosnan, Rosario Dawson, Steve Coogan, Joe Pantoliano, Uma Thurman, Joe Pantoliano. 119m. (Bill Stamets)