In a remote Spanish mountain village, Ruth Miller shelters a drifter in her home while her husband is away. When he playfully masks his face with a Charlie Chaplin mask and she orders him to leave, the encounter takes a brutal turn as he stabs her to death.
Meanwhile, teenage Christine "Chris" Miller is recovering from a nervous breakdown after a violent rape, the trauma intensified by the moment her father abandoned her and her American stepmother Ruth. Recently discharged from a psychiatric institution, she moves into the sprawling country home with Ruth, trying to rebuild her life.
Barney Webster is discovered sleeping in the barn by Ruth. She initially orders him off, but the charismatic drifter grows on her, and she ultimately hires him to work as a handyman on the property.
Barney begins to press closer to both women, while Chris wrestles with fragmented memories of the assault. He witnesses one of her flashbacks in the basement during a heavy rain, and Ruth blames him for triggering the episode, forcing him to leave at gunpoint.
A mysterious man in a black rain shawl arrives at a nearby farm, steals a sickle from the barn, and the young son mistakes him for a monk before unlocking the front door for him. The intruder proceeds to murder the parents and the teenage siblings, culminating in the brutal killing of the youngest child. The morning after, Ruth and Chris see news footage of the murders and immediately suspect Barney.
That night, Barney returns to the Millers' home. Ruth wakes, Chris investigates, and the two end up having sex in Chris’s room, an act that unleashes another tide of memories for Chris. In a frenzy, she stabs Barney in the back with a knife from her nightstand, and Ruth, assuming the killer is Barney, joins in with multiple stabs.
Barney staggers through the house nude, dies from his wounds, and the two women carefully reconstruct their story as a self-defense killing. On the way to the police station, they learn that the actual murderer has been apprehended, and they horrifiedly realize that Barney was not the killer.
Back at their home, Ruth and Chris sift through Barney’s belongings and uncover that he had recently been released from prison and was an acquaintance of Chris’s father. Ruth surmises that Chris’s father sent him to surveil the women and to abscond with a cache of pearls and other family heirlooms.
That night, the two bury Barney’s corpse at a construction site where a road is being built. They watch from a distance as workers pave over the area. The next morning, as Ruth and Chris sit by the pool, the construction crew notices a sinkhole in the road and begins to dig it up, exposing the danger still lurking beneath the surface.
