The Last Mimzy

“The Last Mimzy” is science-fiction for kids, which means a couple things. First, I suspect a lot of it will go over some children’s heads. Second, since it’s a kids’ movie, it’s OK that the conflicts are resolved easily and that the young protagonists are never in any serious danger. You want a little more thrill in a regular sci-fi flick, but for kids, this one’s OK.

Based rather loosely on an old short story by Lewis Padgett (the pen name of husband-and-wife writers Henry Kuttner and C.L. Moore), this charming, intelligent adventure is about 10-year-old Noah (Chris O’Neil) and his little sister Emma (Rhiannon Leigh Wryn), Seattle kids who find a strange box on the shore while spending Spring Break on a small island off the Washington coast. The box looks alien in design and contains a few odd toys and a stuffed bunny rabbit that can, apparently, talk to Emma. What’s more, the toys look and sound different to the kids from the way they appear to everyone else.

Soon Noah and Emma are exhibiting unusual talents. Noah doodles patterns on the back of his school work that are identical to ancient Tibetan mystical schematics. Emma can communicate telepathically. Noah can control spiders. Emma can levitate. And they know, through the stuffed rabbit (called Mimzy), that someone, somewhere, needs their help with something.

The kids’ parents (Joely Richardson and Timothy Hutton) and Noah’s science teacher (Rainn Wilson) are eventually involved, as is the FBI: Evidently you can’t use the space toy you found at the beach to inadvertently cause a massive power outage without the feds thinking you’re a terrorist. Emma remains sublimely childlike through it all, wanting nothing more than to play with Mimzy, and as her big brother, Noah must evolve from nerd into protector.

It’s refreshing that the film doesn’t take the usual route of having the kids’ ideas and abilities doubted by the adults. I always get frustrated watching that kind of movie, knowing that the truth will inevitably come out and wishing the grown-ups would quit being so obtuse. “The Last Mimzy” lets the adults catch on fairly soon, and Emma is so delighted to have magic powers that she doesn’t even try to hide them. (Her brother is a bit more circumspect, at least at first. He’s old enough to know how adults usually react to strange or magical things.)

Li’l thespians Chris O’Neil and Rhiannon Leigh Wryn give sweet, unselfconscious performances as Noah and Emma, and the adults do more than just bumble around the fringes, the way grown-ups in kids’ movies often do. There are weak spots in the story — for example, the children’s father’s workaholism is established and then never addressed — but it’s such a fun story, and there’s so much warmth in the characters’ relationships with one another, that it hardly matters.

B (1 hr., 36 min.; PG, mild peril and shenanigans.)