MIAMI - Olivia Cooke is doing just fine, though the actress didn’t look it in “The Quiet Ones,” not playing in metro theaters.

Ah, the power of movie magic. The ‘Bates Motel” star plays Jane Harper, a disturbed young woman who may be possessed by a doll named Evey (short for “Evil” _ get it?). Jane is the subject of “The Experiment,” conducted by an unorthodox Oxford University professor played by ex-“Mad Men” star Jared Harris, who may or may not be a phony. “The Quiet Ones” is said to be based on actual events _ according to production notes, a 1972 Canadian study attempting to prove that supernatural events are just a state of mind.

“My character had to look dirty, gaunt, hollow, pale and sickly,” says Cooke from the Soho Beach House Hotel. “It was two hours in the makeup chair just to get my hair that greasy. Jane had to be as 3-D as possible.”

Harris was impressed by his co-star.

“That was a tough part to play, very draining,” he explains. “You have to be in such a dark place all the time _ bandaged up, suicidal. After a while that stuff starts to get you down.”

That said, everyone in the cast and crew thought the role of Jane was a star-making opportunity.

“The movie wouldn’t work if the absolutely right person wasn’t in that spot,” Harris says of the 20-year-old doe-eyed brunette. “There was something very special about what she was doing.”

As for his character, the 52-year-old London-born actor _ screen great Richard Harris’ son _ relished taking on the randy, chain-smoking Joseph Coupland.

“There are so many layers to him,” says Harris, who is also co-starring in an upcoming “Poltergeist” remake. “You get to take a ride, because he changes so much throughout the movie. The structure of the story and the way it approached the subject of the supernatural is what really appealed to me. It was juicy!”

Was Coupland based on anyone in particular?

“I think a bit, yes,” he admits. “I went to a Catholic boarding school from the age of 7. It was run by Benedictine monks, and there were certainly some interesting teachers there. But at the end of the day, even if you’re playing a semi-historical figure, it has to come from an exercise in imagination.”

All those cigarettes _ not the healthiest prop.

“I think they were an excuse for the cinematographer to create that ’70s-period feel,” Harris says, adding, “You could also see how my character was handling a certain level of anxiety, if you like.”

Speaking of anxiety, if you live in a house with dolls around, you may want to do a bit of housecleaning after you see this flick.

“What is it about dolls? They’re babies, which are so innocent but have lifeless eyes,” muses Cooke, who remembers being creeped out by a Furby while growing up in Manchester, England. “Wherever you go, those eyes follow you about the room.”