Uneven in tone and full of action, “Hansel & Gretel: Witch Hunters” is an above-average fever dream of a movie that’s a grownup nod to a grim fairy tale.

The story, which is sprinkled liberally with anachronisms and quasi-cyberpunk gizmos, begins with the young siblings being led into the woods by their father and deserted there together. The two, naturally, stumble into a cottage made of candy, where a ghastly witch imprisons them.

They figure out early on how to kill a witch: Burn her. And as they save their own lives, they begin a career as witch hunters. Their latest assignment is from the mayor of Augsburg (Rainer Bock, “Inglourious Basterds”): Figure out who is kidnapping local children.

Jeremy Renner (“The Bourne Legacy”) is a terrific actor, and he gives his Hansel character such a tongue-in-cheek approach that you can’t help but like him. Gemma Arterton (“Prince of Persia: The Sands of Time”) is his resourceful, no-nonsense sister Gretel. Both carry high-powered weaponry (for the period in which this is set, that is) and are expert shots. She carries a sort of automatic crossbow and he carries a kind of arm cannon.

Peter Stormare plays the sheriff in these parts (Stormare, probably best known for his role in “Fargo,” gets the daylights kicked out of him here. Interestingly, you can watch him get the daylights kicked out of him on a neighboring screen in the latest Schwarzenegger vehicle, “The Last Stand.”)

Hansel and Gretel have a kind of sidekick wannabe in Ben (Thomas Mann, “Fun Size”), who keeps scrapbooks of the two and is goggle-eyed when he spots them in person. He’s full of questions, but the siblings know they need to concentrate on the whereabouts of the missing children — particularly since some witch trackers have disappeared, too.

Get the Weekender Newsletter

Plan your weekend with our hand-picked list of the Quad Cities' best bets for entertainment.

I saw the movie in 3-D, and I must admit that the gory slayings are enhanced by the effect. The CGI-created characters, including many witches and a troll who’s like a depressed cousin of Shrek, were OK, but they seemed to be just that: CGI characters.

It’s obvious that this is being considered the first part of a franchise. It’s a good enough time to be worth a matinee or a rental, but it’s not sweet enough for a second outing.