This is the story of the Grace family: mom Helen (Mary-Louise Parker), sister Mallory (In America’s Sarah Bolger), and twin brothers Jared and Simon (both played by Freddie Highmore). They move into the ancient home of their great, great uncle, the late Arthur Spiderwick (David Strathairn) after Helen divorces the kids’ father. Jared, in particular, takes the situation hard, and he has developed some problem behaviors as a result.

While rummaging through the house, Jared discovers a hidden room filled with uncle Arthur’s possessions. Among them is a dusty old book, sealed shut and bearing a warning that it should never be opened. Of course, the kid opens it anyway. Inside, he finds documentation of strange and unusual creatures that Arthur believed to exist alongside humans. It seems like a lot of foolishness until Jared encounters Thimbletack (voiced by Martin Short), a little troll-like creature who has spent decades guarding the book.

To make a long story short - and to avoid too many spoilers - an evil ogre named Mulgrath (voiced by Nick Nolte) desires the book for his own heinous purposes. An army of disgusting creatures does his bidding and starts to attack the Grace home in search of the now-opened book. Jared and his siblings must band together to fight them off. Assisting them are Thimbletack and a benevolent bird-eating warthog named Hogsqueal (voiced, hilariously, by Seth Rogen). In the process, the kids discover some startling facts about their distant relatives and themselves.

Does this sound like a fun story? I hope I have done it justice, because The Spiderwick Chronicles entertained me from one end to the other. I’m tempted to say that it’s the kind of movie I would have loved as a ten year-old child, but I’m a little older than that now and I still love it. I am somewhat amazed at how dull and leaden some of the other recent fantasies have been. (I’m talking to you, Golden Compass!) In contrast, Spiderwick is light on its feet, careening from one moment of excitement and discovery to the next. The story nicely mixes action with some strong character- and story-driven moments. The end result is family entertainment with some substance to it.

Let me rephrase that; it’s entertainment for most of the family. Very young kids are likely to be scared by some of the ugly creatures and the peril that the Grace kids find themselves in. When the movie was over, I was stunned to learn that it’s only rated PG and not PG-13. Considering the evil gremlins are dispatched in sundry ways and occasionally lose appendages in the process, Spiderwick would seem to be inappropriate for youngsters under the age of nine or ten.

Older kids will surely dig it, though, and adults will likely find it enjoyable as well. Director Mark Waters (Mean Girls) effectively stages the action scenes for maximum excitement, and the pacing is relentless, with much-appreciated breaks for humor and plot development.

Then there are the creatures themselves. As audience members, we’ve become used to CGI creations from Jar-Jar Binks to the Cloverfield monster. The creatures in Spiderwick felt more carefully conceived to me, especially Thimbletack. You can sense that their physical looks were created to emphasize their personality characteristics, and not just to look cool or to show off the technology. For that reason, I bought them as part of the story’s reality, rather than just seeing them as CGI trickery.

Underneath all the action and the visuals is a very sweet story about how Jared heals his family and himself. Freddie Highmore has kind of cornered the market on playing wide-eyed kids who discover wonderful worlds; he assumed a similar role in Charlie and the Chocolate Factory and Arthur and the Invisibles. But, unlike a lot of child actors, he’s got some emotional heft. Highmore never comes off as a generic “cutesy” kid. His talent and ability to play characters who feel the weight of the world on their shoulders helps to give The Spiderwick Chronicles some extra depth.

Are audiences growing tired of fantasies? The box office grosses of Golden Compass and The Seeker suggest that’s a real possibility. I hope they won’t be hesitant about checking out this one, however. The Spiderwick Chronicles is fast, funny, and clever, with memorable creatures to sweeten the deal.

( out of four)

The Spiderwick Chronicles is rated PG for scary creature action and violence, peril and some thematic elements. The running time is 1 hour and 37 minutes.