Though he seems to try his damnedest to be one of those annoyingly frisky and ingratiating child actors, I just can’t help but love Jonathan Lipnicki. The lispy little guy who informed us how much the human head weighs in Jerry Maguire is still a self-conscious performer rather than a natural actor, but he takes on his first action role with an appropriately boyish giddiness that’s sure to make him a hero to the elementary-school set. Tony Thompson (Lipnicki) has barely settled in from a move from San Diego to Scotland with his affable but clueless parents (Pamela Gidley: Jane Austen’s Mafia, and Tommy Hinkley) when he befriends Rudolph (the charming Rollo Weeks), who, as a member of the local vampire coven, has been 9 years old for 300 years. Soon enough, Tony has inveigled himself into the good graces of Rudolph’s gothy-punk vampire parents (Richard E. Grant: A Christmas Carol, and Alice Krige) and siblings (Anna Popplewell and Dean Cook) and is embroiled in a plot to grant the family its greatest wish: to be human again. Ancient curses, lost amulets, mysterious coats of arms, and buried treasure make for a delightful fantasy kids will love, and one that won’t make their parents sorry they came along for the ride. Based on the beloved children’s books by Angela Sommer-Bodenburg, this is a sweetly scary and silly story about kid adventures grownups never know about, the secret world of a child’s bedroom, and visions of revenge against bullies — one that doesn’t need to resort to toilet humor or inane slapstick to entertain the kiddies. It’s aimed pretty squarely at the under-12s, but adults will appreciate the nods to movies past, like the Mad Max-esque vampire hunter Rookery (Jim Carter: Shakespeare in Love) and the requisite torch-wielding peasant mob — it simply wouldn’t be a vampire movie without one of those.