Although kind of a blessed relief in a cinematic sea of summer bombast, this contemporized take on the pre-fab teenybopper light mysteries that also brought us the tweener entertainment of The Hardy Boys is about as slight and airy as its source material. Here, the teenaged super sleuth and her doting and well-to-do father are uprooted from River Heights and set back down in the Hollywood Hills. Fortunately, they landed in a spooky old mansion that Scooby and the Mystery Inc. gang hasn’t gotten around to investigating yet. Which means flickering candles indicating the presence of hidden passages. Along the way, she picks up a comic-relief sidekick (because Julia Robert’s niece plays the straight) and goes about being the confidant fish-out-of-water at the local high school. The target demographic will probably miss a lot of the retro-wit on display here, but there’s still enough at play to make for a pleasant matinee time killer.