Suave private detective Simon "The Saint" Templar arrives in San Francisco and meets Val, a woman whose police inspector father killed himself after being accused of corruption and dismissed from the force. Convinced of the man's innocence, Templar takes it upon himself to vindicate the memory of Val's father. To do so he must take on the city's most dangerous criminal gang, while also battling hostile members of the police department.
On a train headed for England a group of travelers is delayed by an avalanche. Holed up in a hotel in a fictional European country, young Iris befriends elderly Miss Froy. When the train resumes, Iris suffers a bout of unconsciousness and wakes to find the old woman has disappeared. The other passengers ominously deny Miss Froy ever existed, so Iris begins to investigate with another traveler and, as the pair sleuth, romantic sparks fly.
A chemical manufacturer is killed just after asking detective James Wong to help him. So detective Wong decides to investigate this as well as two subsequent murders.
An investigator for the District Attorney's office quits to open his own detective agency. However, business is so bad that he finally decides to give it up and go back to his old job. As his wife is at his office closing up, a wealthy society matron walks in with a case: she wants to know if her husband is having an affair with his ex-girlfriend, who is now married. The wife accepts what looks to be an easy case, figuring than she can then persuade her husband to re-start the agency. However, when the client's husband is found murdered, she decides to investigate the murder herself. Her husband has also been assigned by the D.A. to investigate the murder, and he doesn't know that his wife is also on the case. Complications ensue.
Wealthy widow Mrs. Bramson notices that her maid is distracted, and when she learns the girl's fiancé, Danny, is the reason, she summons him in. Mrs. Bramson's niece Olivia takes a liking to Danny, and comes to believe that he may have been involved in the disappearance of a local woman.
Nick and Nora Charles investigate when Nora's cousin reports her disreputable husband is missing, and find themselves in a mystery involving the shady owners of a popular nightclub, a singer and her dark brother, the cousin's forsaken true love, and Nora's bombastic and controlling aunt.
Richard Hanney has a rude awakening when a glamorous female spy falls into his bed - with a knife in her back. Having a bit of trouble explaining it all to Scotland Yard, he heads for the hills of Scotland to try to clear his name by locating the spy ring known as The 39 Steps.
Sir Borotyn, a prominent Prague resident, is discovered murdered in his home, with all indications pointing to a vampire assault. The victim's friend, Baron Otto, and the physician who analyzes the body are certain that the vampire is the mysterious Count Mora, or perhaps his daughter, but receive little help from the law. Professor Zelen, an expert in the occult, is called in to assist with the investigation.
In a spooky hotel on the coast of France, two bands of crooks are working independently of the other in an attempt to steal the inherited fortune of an American girl, Sue Tally. Along the way the heiress is kidnapped, three murders are committed, a girl appears in two places at once, mysterious persons roam about the old hotel at night and mysteriously disappear, and there is a hidden room without any doors.
While vacationing in St. Moritz, a British couple receive a clue to an imminent assassination attempt, only to learn that their daughter has been kidnapped to keep them quiet.
After the death of a gangster, those familiar with his million dollar stash start mysteriously dying. Police detectives with the help of a clairvoyant try to determine who, living or dead, is responsible.
As the demand for raw silk goes sky high, crooked businessman Wallace Myton corners the market with plans to drive up the price. Determined to fulfill his contracts, manufacturer Donald Kilgore imports $3 million worth of silk to Seattle and accompanies it by special train to New York. But when his secretary is found murdered, Kilgore soon discovers Myton has planted three killers on board with orders to stop the express and its passengers dead in their tracks.
Con-man Chandler and his partner Frank decide to start a clairvoyant act. Chandler falls for Sylvia, one of their marks, but their relationship is challenged when his deception impacts others' lives and Sylvia urges him to reform.