But then something wonderful happened: Nanny McPhee appeared, and suddenly her loving sternness and quiet refusal to acquiesce to wiles of juveniles assured me that this was not to be yet another of those horrible movies in which children are monsters but we're supposed to find them adorable anyway. Oh, no, indeed not: This is a delightful movie about children who start out as monsters (for don't they all, after all?) and the adult who not only turns them into reasonable facsimiles of civilized human beings but actually makes them love her for it. (Which isn't to say that children should be molded into submissive automatons, either -- we get to see the comic comeuppance of those who feel that way here, too.) This is a fairy tale, sure, but it's one aimed as much at parents who let their near-feral children run wild as it is at the little savages themselves.

Of course, it should be Firth's (Where the Truth Lies, Bridget Jones: The Edge of Reason) Mr. Brown -- who is, it has been noted, the little savages' sole remaining parent -- who does the whipping into shape, but clueless and ineffectual widowed fathers are, I believe, required by the fairy-tale code.

Don't be thinking Disney, though -- this is more Brothers Grimm, a fairy-tale freakout that goes deeper into the dark woods of the child's psyche than the Mouse usually does. The comparisons to Mary Poppins may be inevitable, but Nanny McPhee has more in common with Willy Wonka and the Chocolate Factory (the Gene Wilder, not the Johnny Depp) than it does with anything chim chim cheree or supercalifragilisticexpialidocious. This is a kiddie movie that's as much cautionary tale as it is lullaby: Mr. Brown is a mortician, and constant reminders of death and violence surround him and his family, from how he sentimentally keeps the pillow on his dead wife's easy chair plumped, as if she'd just stepped out for a moment and would be right back, to the stuffed brown bear that rears up into attack position in his funeral parlor. Things don't so much happen to the Brown children here are they threaten to happen: when the eldest, Simon (Thomas Sangster: Tristan & Isolde, Love Actually), comes to Dad's workplace for a heart-to-heart (their relationship hasn't been so great since Mom died, but you knew that already; it's traditional in these kinds of stories), there's a corpse lying on the slab there between them the whole time, as if to suggest to Simon that Dad could be taken by Death at any time, too. And then there's Mrs. Quickly (Celia Imrie: Wimbledon), the widow Mr. Brown is reluctantly wooing, a dreadful, greedy, grasping nightmare of a creature who hovers over the Brown family like a carrion eater, a symbolic warning to the Brown children of adult malice, as is their Great Aunt Adelaide (Angela Lansbury), herself looking like some great flesh-eating vulture, who will withdraw her financial support of the family if Mr. Brown does not marry again within a month and give the children a new mother.

Oh, it gets so that even all the visual curlicues and vivid acid-neon colors the film soaks in become menacing. But never Nanny McPhee. The children, of course, see her as something less than Mary Poppins-ish, at first -- she does not have rosy cheeks, and she definitely does have warts (though they soon learn to see her through new eyes). And, man, there is absolutely no spoonful of sugar to make her medicine go down, not actually -- "It's mooo-viiing!" one of the kids screams about the black goo she doses them up with when they fake the measles -- and not metaphorically: when it seems she's loosened up a bit on her no-naughtiness rule to let the kids launch an attack against the impending nuptials of their father and Mrs. Quickly, it turns out there's a hard lesson to be learned there, too.

Emma Thompson (Harry Potter and the Prisoner of Azkaban), who also adapted the script from Christianna Brand's Nurse Matilda books (Thompson also did an uncredited pass on the screenplay for the recent Pride & Prejudice), makes Nanny McPhee a supremely self-possessed woman, a mother figure whose magic is not so much about her weird powers but about her capacity to love, her fantastical ability to make a donkey dance notwithstanding. Yup, there's plenty silly stuff here to keep the little tykes entertained while the sly lessons about what makes for compassionate, polite, civilized children settle onto the little ones, and their parents, too.