The greatest monsters are the ones grounded in reality. Long before his character reveals anything supernatural in his makeup, the mysterious antiques dealer played by Timothy Spall has given us a vibe.

Pervert. The sort who lures children into cars and, in his care, shipping containers that he uses as his “shop.”

His character is obviously the villain of “The Changeover,” something we pick up on in an instant. We don’t have to be like Laura, “Lolly” to friends and family, a girl with “a gift” to see it.

“I feel in my bones when something bad is going to happen.”

Laura’s like her dad, someone who sees things, picks up warnings. Mum (Melanie Lynskey) considers that nonsense and doesn’t take her any more seriously than she did Laura’s father. Even though dad saw the Christchurch, New Zealand earthquake coming and knew it’d be the end of him.

“The Changeover” is a moody, menacing thriller with a YA (Young Adult) heroine. It could have been “Twilight Lite” with 16 year old Laura (Erana James) learning about herself, just “what” she is, and about love from the pouty-hunky classmate (Nicholas Galitzine) who seems to have the answers.

From Laura’s understated but chilly voice-over narration, to the driving menace of the movie — her five year old brother’s mortal peril –“Changeover” is a story that works, no matter how familiar and limited — claustrophobic — it feels.

The late novelist Margaret Mahy crafted a smarter, more writerly precursor to “Twilight,” beating the American pulp novel to the shelves by decades. Kiwi filmmakers Miranda Harcourt and Stuart McKenzie have updated the 1984 story, putting Laura Chant and her family in Christchurch, N.Z., not long after its recent catastrophe.

“The earthquake broke our city,” Laura narrates. “It broke our family, too.”

Laura experiences premonitions, and the latest is about her brother. Mom won’t hear it.

“Your paranoia is off the Richter Scale.”

With Mom working all hours, Laura has to keep an eye on young Jacko (Benji Purchase). She’s quite responsible for her age, but he’s at that run-ahead-of-you/escape your sight phase, and Laura can be distracted.

That’s how she finds Jacko in the presence of evil. But she still lets the creep, sixtysomething and awfully solicitous of children, put a stamp on Jacko’s hand.

No, that’s not the butterfly he promised. No, it won’t come off. And no he’s not telling her the truth.

“I’m not going to hurt you, Laura!”

As her brother starts acting out and even speaking in the old creep’s voice, Laura has to seek the help of a good-looking classmate, Sorenson (Galitzine). He’s sort-of flirted. He’s warned her, telepathically. Maybe he has some answers.

And if not him, maybe his spooky mom (onetime “Warrior Princess” Lucy Lawless) or his grandma (Kate Harcourt).

For all its exposition and the novel names for the strange beings we’re meeting, “Changeover” — the title is a transition Laura must make to save Jacko — cannot escape the feeling that we’re watching “Twilight with Witches.” But it instantly feels more real, more lived-in and more unnervingly claustrophobic by means of a production that goes easy on effects and never paints its leading man in glitter.

James makes a fiery heroine, established in an early scene as a bit of an adrenaline junky, fiercely protective of her brother but still a typical teen — in open rebellion against a mother who just doesn’t “get” her.

Lynskey, one of the most versatile actresses to come from New Zealand, wonderfully gets across a mother both overwhelmed and entirely too eager to pass heavy responsibilities on to her teen daughter.

“I’ll be the mom.”

“Do you even know HOW?”

Galitzine seems tailor-made to poster a million teen girl bedroom walls (He starred in a comedy called “Handsome Devil,” for obvious reasons.).

But it is Spall, as he proved in the Harry Potter pictures (Wormtail) and in the recent “Denial,” makes a wonderful villain and as such makes the somewhat over-familiar “Changeover” worth your while.

When he bugs his eyes out and grins that viperous, British-dentistry grin, you know it’s time to hide the kids and cross the street to avoid him. Even before he whips out his hand-stamp.

MPAA Rating: unrated, for mature audiences

Cast: Erana James, Timothy Spall, Melanie Lynskey, Nicholas Galitzine, Lucy Lawless

Credits: Directed by Miranda Harcourt, Stuart McKenzie, script by Stuart McKenzie, based on a Margaret Mahy novel. A Vertical Entertainment release.

Running time: 1:32