Mrs. Philip Mason commits suicide after she has an affair with Stephen Lee, a disreputable stockbroker, and sells her husband's securities so that Lee can buy stocks. When Lee goes bankrupt, he blackmails Helen Trent by threatening to reveal silly love letters she wrote to him before she married. Her brother, Willy Grosby, and his fiancée, Helen O'Neil, who lives with the Grosbys, go to retrieve the letters. While Willy waits outside, Lee is knifed to death as he attacks Helen. Lee's friend, Edward Wales, attempts to pin the murder on Helen by having Madame LaFarge, a clairvoyant, conduct a séance. In the darkened room, Wales, through whom Lee's spirit supposedly speaks, is about to name Helen as the murderer, but Wales, who sits in the thirteenth chair, is himself murdered. After Helen confesses to Inspector Donohue that Madame LaFarge is her mother, LaFarge, while conducting another séance, tricks Philip Mason into confessing to the murders.

The compound of an arms manufacturer turns into a zombie nightmare when its workers are given the wrong formula.

Slowly dying of an unspecified illness, wealthy invalid Charles Sellon wants his aide Neil Hamilton to end his suffering. Hamilton won't do it, but villainous lawyer Alan Dinehart, in line to inherit Sellon's millions, is not so charitable. Dinehart kills Sellon, then makes it look as though Hamilton murdered the old guy for his money.

Homicide detective Melanie Hudson begins a torrid affair with a senator's son who is a suspect in a series of grisly murders.

Jake Kimble, the sole survivor of the Chicago massacre, is killed while in solitary confinement. His doctor begins investigating the claims he made about a long-haired woman in white, as a mysterious Japanese woman arrives at his old apartment building to help them get rid of the curse.

Seattle medical examiner David Krane is obsessed with solving his wife's murder. A possible solution presents itself in an experimental "memory" serum designed by a neurobiology professor, which has the ability to transfer memories from one person to another, but with potentially fatal consequences.