Clive Riordan, a wealthy London psychiatrist, learns that his wife Storm is cheating on him with an American, Bill Kronin. He determines to get the perfect revenge on both of them by committing the perfect murder of Kronin.
Kidnapping Kronin at gunpoint, Riordan keeps him prisoner for months in a hidden room while authorities mount a search for the missing man. Riordan reveals to Kronin that he plans to kill him and dissolve his corpse in an acid bath to ensure no evidence remains to be found. Riordan's plot appears to succeed until a superintendent from Scotland Yard visits the doctor's office enquiring about the case and hinting that he knows what Riordan is up to, having been tipped off by an anonymous letter to the Yard.
One involves wanted fugitive Joe Walpo, who has killed a gas-station attendant. Another concerns a department store fashion buyer, Kate Martell, who is being extorted by a man threatening to kill her daughter. A third has to do with a gang of thugs who hijack cars.
Ripley and his new partner trail Connie Anderson, a girlfriend of Walpo's, to his hideout, where Ripley shoots him. They tie up the car-jacking case and are then able to narrow down who the killer of the FBI agent must be.
They follow Kate to the "Hollywood" sign in the hills above Los Angeles, where she has been told to bring the money. There the extortionist is revealed to be a man named Milson who had shown a romantic interest in Kate, leading to a confrontation with Ripley.
Distraught after her second miscarriage and learning definitively she could never have children, Paula Rogers, while driving at night, accidentally injures a child. Confused and also expected to attend a function that honors her husband, Paula doesn't follow the child to the hospital as she should. She attempts to tell her husband about the incident but has trouble finding the right time.
Later, overcome with remorse, she looks to get close to this child and becomes a helper at the hospital. The child is an orphan with limited health care available. The doctor recognizes Paula's need to be useful and asks if she would become his speech therapist and guardian. She finds meaning and purpose in her life as she engages the little boy in intensive therapy necessary to recover his ability to speak.
(Don't miss the sequel: Paula, Part 2 - Davy's Revenge)
