Three secretaries have quit working for Mr. Conklin. A fourth is expected today. Meanwhile, there might be a "dancer" named Mitzi Leroy at the stag party being planned for Mr. Conklin's brother-in-law.
A lonely boy befriends a giant spider. Soon after, he also tries to romance a girl in the small room, but she screams of shock and runs out the building when she notices the spider. The giant spider comes out to attack and Cranston shoots it dead. The boy is upset by the death of his "friend." Suddenly, the "power of revenge" is transmitted from the spider.
Lamont Cranston and Margot Lane watch a play where a woman poisons herself after she is arrested for murder. After the show, Lamont and Margo go to a local saloon with the playwright, and soon after, are involved in a case where murders, like the ones scripted on the stage, begin to take place.