An unemployed drifter, Eric Stanton wanders into a small California town and begins hanging around the local diner. While Eric falls for the lovely waitress Stella, he also begins romancing a quiet and well-to-do woman named June Mills. Since Stella isn't interested in Eric unless he has money, the lovelorn guy comes up with a scheme to win her over, and it involves June. Before long, murder works its way into this passionate love triangle.
Julia Ross secures employment with a wealthy widow and goes to live at her house. Two days later, she awakens in a different house in different clothes and with a new identity.
Ten strangers are summoned to a remote island and while they are waiting for the mysterious host to appear, a recording levels serious accusations at each of the guests. Soon they start being murdered, one by one. As the survivors try to keep their wits, they reach a disturbing conclusion: one of them must be the killer.
After the King of Rovenia has been assassinated, Holmes and Watson are engaged to escort his son to Europe via Algiers, aboard a transatlantic ocean liner which also carries a number of suspicious persons, any of whom may be involved in a plot to also assassinate him.
Sherlock Holmes investigates when young women around London turn up murdered, each with a finger severed. Scotland Yard suspects a madman, but Holmes believes the killings to be part of a diabolical plot.
A feud between rival newspapermen Kruger (Bromberg) and McDonald (Guilfoyle) goes deadly when blackmailing McDonald ends up murdered and his corpse planted in the trunk of Kruger's car. Good guy Kruger attempts to hide McDonald's body, with the help of chauffeur Hogan (Jenks), to keep from being charged with murder. However, zany scenarios occur as the body just won't stay hidden, and keeps on popping up in multiple places where Kruger is located, leading to him hiding the body again and again while Kruger tries to find the real killer.
An estranged wife shows up after a nearly 7 years of disappearance -- thought to be dead, to prevent her husband from marrying his new love until someone kills her.
Leo, a former convict, is living in seclusion on an island with his step-daughter, the daughter of his late wife. Leo was framed by a group of former business associates, and he also suspects that one of them killed his wife. He has invited the group to his island, tempting them by hinting about a hidden fortune, and he has installed a number of traps and secret passages in his home. He is aided in his efforts by a former cell-mate who holds a grudge against the same persons. When everyone arrives, the atmosphere of mutual suspicion and the thick fog that covers the island promise a tense and hazardous weekend for everyone.
Leslie Calvin, the sole survivor of a submarine accident, goes to her relatives in order to recover emotionally. Unfortunately, she encounters various scam artists led by Mr. Sydney who intend to kill her and steal the family assets. Dr. George Grover helps Leslie to defeat Sydney.