Handsomely mounted, beautifully cast and tautly directed, “My Cousin Rachel” gives us a piece of British cultural history in the form of a chilling period mystery. Heavy with the weight of cruelty that we feel certain is coming, it shows that jealousy, suspicion and heedless desire may put even the most beautiful people in jeopardy, and that simple naiveté might have menacing effects.

Based on the novel by Daphne du Maurier (whose bookshelf has given us such haunting films as “The Birds,” “Rebecca” and “Don’t Look Now”), it plays like a fever dream wrapped inside a sharp thriller. Set in rural England in the 1830s, it is about a love affair that slowly, surely builds to tragedy.

At the center is Philip (Sam Claflin), the young, handsome new heir to the vast estate of his late cousin who, after the deaths of Philip’s parents, became his adoptive father. A bit unformed but well-intentioned, Philip deals respectfully with the army of servants and workers he has inherited, and begins to learn to be a proper lord of the manor.

He moves to a harder task as he attempts to explore the reasons for his cousin’s death, which came under dubious circumstances while on an extended visit to Italy for his health. He married there suddenly, leaving his lifelong bachelorhood, and has left behind a beautiful and penniless widow, Rachel, an English/Italian exotic. The character isn’t introduced until the film’s second act, but her reputation is widely discussed in contradictory terms. Everyone has a different version of Rachel, painting her as a beloved ideal, a vulnerable innocent or a manipulative sexual libertine with her eye on aristocratic wealth.

As perceptively played by Rachel Weisz, she is accomplished, captivating and almost indefinable. When she arrives to hold her period of mourning at the family estate with Philip, director Roger Michell (“Notting Hill”) frames her at some times creeping around the dark mansion like an intruder, at others entertaining parties of delighted guests with irresistible charm. She is an enigma to most men, but so lustrous and beautiful as to be a source of dread and resentment for most women.

As seen through Philip’s gullible viewpoint, she is impressively mature, magnetically attractive and, as the story progresses, increasingly frightening. Letters from Philip’s late guardian surface, implicating Rachel in sinister schemes. But are notes from an unhealthy man to be taken more seriously than the accusations of shame aroused by Philip’s increasingly passionate courtship of the newcomer?

Michell applies a Hitchcockian level of anxiety. We are kept as confused as Philip while he tries to piece together the puzzle. The splendid production design draws us into a world where fine dress could conceal dangerous thoughts, baleful intentions were expressed in the most genteel way and unrequited love could carry the darkest consequences.