After a dearth of good movie previews, the sea god Poseidon (Kevin McKidd) strode like a leviathan into modern Manhattan, where he treated with Zeus (Sean Bean) over the chief god's stolen lightning bolt and the fate of the world.

Flip to Percy Jackson (Logan Lerman), sitting at the bottom of a swimming pool, completely unaware that he's the son of Poseidon and, at the same time, setting a fire among young girls who've gotten over Daniel Radcliffe and have decided Robert Pattinson is just too damn depressing. Percy is dyslexic, has unresolved daddy issues and can hold his breath underwater for impressive lengths of time. Ironically, even as Percy is learning about the Greek and Roman demigods Hercules, Achilles and Perseus from his teacher Mr. Brunner (Pierce Brosnan), a Fury is about to bring his father's world crashing down around him.

Brunner, it turns out, is really the centaur Chiron, and Percy's best friend Grover (Brandon T. Jackson) is a disguised satyr (half man, half goat) assigned to protect him. Of course, being a film targeted at a younger audience, The Lightning Thief is required to adhere to the tired device of not telling the hero anything useful until he learns it all for himself.

It turns out there are hundreds of demigods in the world, even though the half-mortal spawn of the Big 3 -- Zeus, Poseidon and Hades -- are rare, and many of them spend their days training at a Greek-themed summer camp that would send Xena fans into a lather. It doesn't matter that they're not actually training for anything; the camp keeps them fit and busy, until Percy comes along and, after one day of sport, decides it's time to go on a quest to find Persephone's pearls, visit Hades (Steve Coogan) to rescue his mother (Catherine Keener), find the missing lightning and confront Zeus in Olympus before the gods go to war and destroy the world. Grover and Annabeth (Alexandra Daddario), a daughter of Athena, come along for the ride, mostly because they're bored at camp.

The movie, based on the first in a a series of novels by Rick Riordan, reveals at one point that Percy's mother spent much of her life after Percy's birth living with a vile and smelly man simply so his odor would mask the scent of Percy's Olympian blood. This begs the question, didn't she ever hear of lavender soap and incense?

Anyway, The Lightning Thief is somewhat rare in that this kid-friendly film has some level of intellectual depth and a great deal more excitement and legitimate plotting than a sparkly vampire could ever provide. There are places where the special effects ring false and the fight choreography seems forced, but overall it's a treat for its age set that won't bore adults in the audience to tears. The young actors did a very good, if not stellar, job with the material, and there are enough Hollywood heavy-hitters in the film to give it a substantial foundation of talent.

Oh, I can't avoid mentioning two brief but impressive appearances in the film: Uma Thurman as a seductive Medusa and Rosario Dawson as a sultry Persephone. Mythological indeed.

I do hope this series continues. So does my 12-year-old daughter, Molly, who loved it even though she still likes the Twilight series and the suicidal Edward Cullen better. Sigh.