The fun of ‘My Cousin Rachel’ is in the wondering who she is

Did she or didn’t she?

That’s the question at the center of many stories, and so it is with “My Cousin Rachel,” Roger Michell’s adaptation of the Daphne du Maurier novel. What makes it so intriguing is that the context of the question, asked at the beginning and the end of the film, changes over the course of it.

A lot changes.

This is based, after all, on the work of Du Maurier, the author of “Rebecca” and “The Birds,” among other things. It’s a period piece set in the 19th century that was written in the mid-20th (a 1952 film version starred Olivia de Havilland and Richard Burton), and the mix of eras adds a lot to it — the agonizing wait for correspondence, etc.

So does Rachel Weisz, who is outstanding as the Rachel of the title. We don’t meet her for quite a while, though. The film begins with young Philip Ashley (Sam Claflin) moving into the estate of his cousin on the English coast. Philip goes off to college, and when he comes back his cousin has taken ill, and heads off to Florence to recuperate.

Then comes word that he has fallen in love with his cousin Rachel, and they marry. Good for him, maybe, but soon letters begin arriving for Philip in which it seems Rachel is controlling her new husband, tormenting him, and soon he is dead of a brain tumor.

And Rachel is coming to England.

Philip is living on her late husband’s estate; he can’t very well keep her away. But he doesn’t have to like it. And boy, does he not like it.

“Whatever it cost my cousin in pain and suffering before he died, I will return in full measure upon the woman that caused it,” he says. Them’s fightin’ words, as they say.

Then she shows up.

The Rachel he meets is not at all like the Rachel of his cousin’s letters. She is smart, independent, free-thinking — traits which do not endear her to everyone; more than one person suggests to Philip, with a wink and a nod, that she’s rather free with her affections. And with other people’s money.

No matter. It’s not long before Philip has fallen under her spell. Or is it a spell? What’s she up to? Philip shows her his cousin’s letters, and she isn’t surprised; he had a brain tumor, after all, and seemed like a stranger to her by the end.

Philip’s circle, in particular his lawyer (Simon Russell Beale) and Louise (Holliday Grainger), the woman whose obvious lifelong love for Philip goes unreturned, are alarmed at Philip’s growing infatuation. He makes decisions that trouble them, and should. Or should they?

Another question.

As it happens, Rachel knows all sorts of herbal remedies, which she puts in teas. Soon Philip begins to grow ill. Is it happening again? Did Rachel kill her husband, and is she now killing another cousin? Or is Philip merely sick, and she is suspected only because she is a woman, with the temerity to strike out on her own?

Claflin is good as Philip, who could not be more inexperienced around women if he had grown up among only men (which he did). It’s easy to see how he might fall victim to his emotions, how he might swing from hate to love so quickly, and go whole hog once he’s made up his mind.

Weisz, meanwhile, is terrific. Michell doesn’t seem as interested in keeping us guessing as he might, but Weisz’s performance is what provides the tension. It’s impossible to read her — or, more accurately, it’s possible to misread her. That’s kind of the same thing, but not quite. The difference could be deadly.

Bill Goodykoontz, USA TODAY Network

★★★

Fox Searchlight presents a film written and directed by Roger Michell, based on the novel by Daphne du Maurier. Rated PG-13 (for some sexuality and brief strong language). Running time: 107 minutes. Opens Friday at local theaters.