Prominent novelist Richard Harland (Cornel Wilde) is released from prison after serving a two-year sentence. He goes to Maine, and is met by his attorney, Glen Robie (Ray Collins), who sends Richard off in a canoe to Richard's lodge, then relates his story to a companion:

A few years ago, while writing a novel, Richard accepted an invitation from Glen to vacation at his ranch in New Mexico. During the train ride, Richard is left breathless by the striking beauty of a socialite, Ellen Berent Harland (Gene Tierney) who comments on his close resemblance to her late father. Richard is greeted at the station by Glen, who reveals that Ellen is also visiting the Robie family with her mother, Mrs. Margaret Berent (Mary Philips), and adopted sister, Ruth Berent (Jeanne Crain). They have come to scatter her father's ashes at his favorite spot in the mountains.

Richard confesses to Ellen that he questioned Glen about her fiancé, attorney Russell Quinton (Vincent Price). She coolly declares she has taken off her engagement ring.

Russell comes to the ranch, having received a telegram from Ellen breaking their engagement, and despite his misgivings, Richard cannot resist Ellen and the couple are married. After a brief honeymoon, the newlyweds travel to Georgia, where Richard's beloved, teenaged brother, Danny Harland (Darryl Hickman), is recovering from polio. Richard is touched by Ellen's attentions to Danny.

At the lodge, Ellen is frustrated by the presence of Danny and Leicke Thorne (Chill Wills), an old family friend, and resents the time Richard spends writing, which spurs a violent, obsessive, and dangerous jealousy in her.

Margaret and Ruth show up, and Richard is appalled by his wife's hostility toward her mother and sister. Ellen even accuses Richard of being in love with Ruth, then tearfully begs for his forgiveness by telling him that she cannot bear to share him with anyone else. Margaret and Ruth leave soon after, and one afternoon, Ellen accompanies Danny on his daily swim in the lake. Ellen follows in a rowboat behind Danny and urges him on, but when a cramp hits the exhausted boy and he cries for help, she watches impassively as he drowns. Richard seems to accept Ellen's explanation that Danny's death was an accident, but as time passes, he becomes mired in a deep depression.

Hoping to rejuvenate Richard's love, Ellen becomes pregnant, and Richard eagerly anticipates the birth of their child. The couple have moved to the Berent home in Bar Harbor, and as her pregnancy progresses, Ellen comes to loathe the baby and fears that it will come between her and Richard. After telling Ruth that she longs for "the little beast" to die, Ellen throws herself down a flight of stairs and causes the death of her unborn baby. Upon Ellen's return from the hospital, Ruth is unable to bear her sister's malevolence any longer and prepares to leave for Mexico, which is the setting of Richard's just-published novel. Furious that the book is dedicated to Ruth and not to her, Ellen confronts Richard and confesses that she murdered Danny and their baby.

When Richard leaves her, Ellen concocts an elaborate scheme to frame Ruth for her "murder," then kills herself with arsenic. Ruth is brought to trial by Russell, who is now the State District Attorney, and Ellen's careful plans, including asking Richard to scatter her ashes with her father's, stack the evidence against Ruth. While she is being questioned, Ruth admits to being in love with Richard but maintains her innocence. Unable to let Ruth suffer, Richard takes the stand and reveals the depths of Ellen's jealous depravity.

The story almost completed, Glen tells his friend at the lake that while Ruth was acquitted, Richard was sentenced to two years in prison for being an after-the-fact accessory to Ellen's unreported crimes.

As Glen finishes the tale, Richard paddles up to the cabin, where Ruth welcomes him with a loving embrace.

A 1945 American psychological thriller film-noir melodrama film directed by John M. Stahl, produced by Darryl F. Zanuck, adapted for the screen by Jo Swerling, based on the 1944 novel of the same name by Ben Ames Williams, starring Gene Tierney, Cornel Wilde, Jeanne Crain, Vincent Price, Mary Philips, Ray Collins, Gene Lockhart, Reed Hadley, Gertrude Astor, Darryl Hickman, and Chill Wills.

Shot in Technicolor. It was Twentieth Century-Fox's highest-grossing film of the entire decade. The film uniquely blurs genres, featuring elements of film-noir, psychological thrillers, and melodramas, and makes numerous visual and narrative references to figures in Greek mythology.

The title is from William Shakespeare's "Hamlet", in which the Ghost urges Hamlet not to seek vengeance against Queen Gertrude, but to "leave her to heaven, and to those thorns that in her bosom lodge to prick and sting her."

The film was selected for the U.S. National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant."