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.
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.
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.
When a treasure hunter seeks a downed airplane in the jungles of Africa, he encounters one of the passenger's young daughter, now fully grown, and with a gorilla protector.
After one member of their group is murdered, the performers at a burlesque house must work together to find out who the killer is before they strike again.
Cosmo Jones, a correspondence-school detective from a small town, comes to the big city to offer his services to the police. He happens by where a gangster is killed by an opposing gang. Socialite Phyllis Blake is running around with gang member Tom and the opposing gang plan on kidnapping her. Cosmo is with Sergeant Flanagan when the attempt is made in front of a night club, where a bystander is seriously wounded in the gun-battle. Police Chief Murphy blames Flanagan for the shooting and demotes him. Cosmo, with the aid of a porter, Eustace and Flanagan's fiancée, Susan, tries to find the killer. Phyllis is finally kidnapped and Cosmo decides the act was committed by one of the two gangs. He has her father place an ad in the newspaper that contact has been made with the kidnappers. Each gang thinks the other is pulling a double cross, and one gang wipes out the other.
In the midst of World War II, Sherlock Holmes rescues the Swiss inventor of a new bomb-sight from the Gestapo and brings him to England, where he quickly falls into the clutches of the evil Professor Moriarty.
The police arrest a man climbing over the wall of a cemetery after midnight. He claims that he is being blackmailed and is following instructions he received by mail to leave $1000 on a certain grave. It turns out that he's not the only one who got a blackmail letter from the same person--calling himself "The Black Panther"--and it also turns out that all the recipients are connected to an opera company.
Henry Courtney, a wealthy importer is found murdered and the famous DeNormand necklace has been stolen. The false testimony of two witnesses, Rand and Hobbs, puts Jim O'Brien in the shadow of the hangman's noose. Martha Courtney, widow of the murdered man and Jim's former sweetheart is convinced he isn't guilty, and promises crooked lawyer Roger Lanning the necklace - which Jim doesn't have - if he can arrange for Jim's escape. Rand and Lanning killed Courtney, but Lanning doesn't know that Rand has the necklace.
Two friends take jobs as truck drivers, unaware that the trucking company is being targeted by a gang of saboteurs who will stop at nothing, including murder, to stop them.
Topper is once again tormented by a fun-loving spirit. This time, it's Gail Richards, accidentally murdered while vacationing at the home of her wealthy friend, Ann Carrington, the intended victim. With Topper's help, Gail sets out to find her killer with the expected zany results.
In the middle of a pictorial lecture on his recent expedition to the Mongolian Desert, Dr. John Benton,the famous explorer, drinks from the water bottle on his lecture table, collapses and dies. His last words "Eternal Fire" are the only clue Chinese detective Jimmy Wong and Captain Street of the police department have to work on.
A none-too-popular (nor good) radio singer, Rita Wilson is murdered while singing on the air in a radio studio. Radio page boy, Frankie Ryan, and his janitor pal, Jeff, solve the mystery for the none-too-sharp police.
Twenty years removed from Alice Barlow's murder by a thief looking for her jewels, newlyweds Paul and Bella Mallen move into the very house where the crime was committed. Retired detective B.G. Rough, who worked on the Barlow case, is still in the area and grows suspicious of Paul, who he feels bears a striking resemblance to one of Barlow's relatives. Rough must find the truth before the killer can strike again and reclaim his bounty.