Dr. Lynn Harper, psychologist, has been called out to the old Ingston Mansion, a dark and mysterious place with a very bad reputation, in order to make an assessment of the sanity of Margaret Ingston, daughter of patriarch Kurt Ingston. She claims to be sane, but she is clearly very disturbed; we can’t be certain, although the doctor gives her a clean bill of health. But then Dick Baldwin shows up on the scene, just when Dr. Lynne has been receiving thinly veiled threats from the inhabitants of the house. He’s our hero. Three medical doctors have been invited out to the mansion as well, Dr. Timmons, Dr. Phipps and the sleazy Dr. King (Lionel Atwill). One by one the doctors are mysteriously murdered. Dick Baldwin must figure out who is doing the killings, and he must do so before whoever it is can kill his new love interest, Dr. Lynne Harper. But the only one he can trust is Kurt Ingston himself, since Ingston has no legs and can’t have perpetrated these murders. Is it sinister Rolf, the butler, or Laurie, the sex crazed and sociopathic chauffeur, or Agor Singh, the Hindu Yogi with his strange ways? And of course, Lynne might be wrong, Margaret may be very insane, and she might be the culprit.
After the death of many brides in their weddings and disappearance of their corpses, the snoopy journalist Patricia Hunter (Luana Walters) notes that all of them were wearing an orchid in their breasts. She finds that the hybridization of the orchid was made by Dr. Lorenz (Bela Lugosi), and she decides to interview him about the flowers. She hitchhikes on the road with Dr. Foster (Tristam Coffin) and they are hosted by Dr. Lorenz in his isolated house. Dr. Lorenz is indeed a mad scientist that sleeps with his wife in coffins, and with the assistance of a dwarf and his strong retarded brother, extract gland fluids from the neck of the abducted virgins to keep his elder wife young.
Ygor resurrects Frankenstein’s monster and brings him to the original doctor’s son, Ludwig, for help. Ludwig, obsessed with the idea of restoring the monster to full power, is unaware that his various associates all have different ideas about whose brain is to be transplanted into the monster’s skull.
A cabal of American industrialists, all fifth-columnists intent on sabotaging the war effort, are methodically murdered by the malevolent Monsieur Colomb. It is only until detective Dick Martin is assigned to the case that everyone’s true motives and identities are revealed.
A practical man returns to his homeland, is attacked by a creature of folklore, and imbued with a malady his disciplined mind tells him can not possibly exist.
The boys are sent to a mountain camp. Stranded in a small rural town, they hear about a “monster killer” roaming the countryside. At night, they sneak out. Peewee is shot by a grave-digger, and they are forced to seek aid at an old mansion. The owner of the mansion (Lugosi), insists that the boys spend the night. After seeing PeeWee walk around the house in a trance, the boys decide that the man turned him into a zombie. They gang up on him and tie him up. The nurse at the boys camp (Dorothy Short) sets out to find the missing boys with Von Grosch (Dennis Moore), who has come to rid the town of the killer- or has he?
It appears the health of wealthy spinster Henrietta Winslow, who lives with her pet cats and mysterious servants, is failing. Her greedy relatives descend on the isolated mansion hoping to inherit a portion of her vast fortune. Joining them is Gil Smith, an enterprising real estate broker who hopes Henrietta will sell him the property and his comic sidekick, Mr. Penny, an idiosyncratic furniture dealer who sees a treasure trove of profitable antiques in the mansion. Henrietta’s doctor surprises everyone by announcing that his patient has defied the medical predictions and is currently in remission, much to the disappointment of her gathered family. Not content to wait until nature eventually takes her course, someone expedites the process by murdering the old woman with a knitting needle.
Dr. Carruthers feels bitter at being betrayed by his employers, Heath and Morton, when they became rich as a result of a product he devised. He gains revenge by electrically enlarging bats and sending them out to kill his employers’ family members by instilling in the bats a hatred for a particular perfume he has discovered, which he gets his victims to apply before going outdoors. Johnny Layton, a reporter, finally figures out Carruthers is the killer and, after putting the perfume on himself, douses it on Carruthers in the hopes it will get him to give himself away. One of the two is attacked as the giant bat makes one of its screaming, swooping power dives.
Kay Kyser and his orchestra are hired to entertain at the birthday party of a young heiress at a creepy old mansion, where they uncover a plot against her life. Who is the villain? The sinister judge? The phony medium? The skeptical psychologist? You’ll find out.
When his friend Professor Kingsely (Ridges) is at deaths door, brain surgeon Dr. Sovac (Karloff) saves his life by means of an illegal operation that transplants part of injured gangster Red Cannon’s brain. Unfortunately, the operation has a disasterous Jeckll and Hyde side effect and under certain conditions the persona of Cannon emerges. Sovac soon learns of the duel personality and of half a million dollars the gangster has hidden away. He attempts to find the money through the manipulation of his friend, an attempt that brings Kingsley closer to madness as he alternates between a meek professor of english and a brutal gangster out for murderous revenge on those who tried to kill him.
In London, the Scotland Yard Detective Inspector Larry Holt is assigned to investigate a serious of deaths apparently in accidents. However, a further inquiry shows that all the victims are men without family and insurance policy released by the insurance agent Dr. Feodor Orloff and the beneficiary is a home for blind administrated by Prof. John Dearborn. When Henry Stuart is found drowned, his daughter Diana comes to London and helps Holt and his American partner Lieutenant O’Reilly in their investigation.
Wolf Frankenstein, son of Henry Frankenstein, returns with his wife, to his fathers estate to claim his inheritance. When he arrives with his family he recieves a hostile reception from locals. While exploring his fathers laboratory he comes across crooked blacksmith – Ygor, who asks him to revive his father’s creation – the MONSTER who is lying in a coma. Wolf tries to revive the monster and believes he fails but then some of the locals are found murdered soon after who just happened to be part of the jury that sent Ygor to the gallows. The villagers immediately connect the killings to Frankenstein and send the inspector to investigate. He discovers the monster is alive and is being used as tool by Ygor. Wolf then in fit of madness shoots Ygor. The then enraged monster losing his only friend kidnaps Wolf’s son. In the end Wolf tracks the monster to the lab where he swings down on a chain knocking the monster into a sulpher pit and thus his demise.
The story (serial and/or feature) deals with the plotting of a European importing firm to put Chinese trade competition in a west coast Chinatown – city unnamed, but it’s by the bay and it isn’t Oakland – out of business. Their representative, Sonya Rokoff/The Dragon Lady (Luana Walters), a beautiful Eurasian girl, hires Victor Poten (Bela Lugosi), a mad Eurasian chemist and inventor and an equal-opportunity racist who hates both Chinese and White races, to aid her. Poten, by means of his infernal inventions and underworld henchmen, conducts successful raids on the Chinese merchants and also successfully eludes the people hunting and investigating him. Those include newspaper reporter Joan Whiting (Joan Barclay), her sweetheart Martin Andrews (Bruce Bennett as Herman Brix), Willy Fu (Maurice Liu), Martin’s servant, and police Captain Walters (Forrest Taylor) and his detectives. After narrow escapes from death in the form of bombs, poison-traps, infernal machines and some hand-to-hand, five-on-one scuffling in Chinatown’s underworld, Martin finally captures Poten just as he is about to indulge in a little wholesale killing by poisoning the wine served at a Chinese merchant’s banquet.
Visionary scientist Janos Rukh convinces a group of scientists and supporters to mount an expedition to the African continent to locate and study an ancient meteorite of great significance. He exposes himself to the highly toxic radiation of the meteorite, and while an antidote devised by Dr. Benet saves him from death by radiation poisoning, his naked touch causes instant death to others. Back in London, the benefits of the meteorite’s controlled radiation offer Dr. Benet an opportunity to restore eyesight to the blind. The antidote’s toxicity excites Prof. Rukh into paranoid rages as he seeks revenge against the members of his expedition, who he accuses of stealing his discovery for their own glory.
James Houghland, inventor of a new method by which television signals can be instantaneously sent anywhere in the world, refuses to sell the process to television companies, who then send agents to acquire the invention any way they can. On the night of his initial broadcast Houghland is mysteriously murdered in the middle of his demonstration and it falls to Police Chief Nelson to determine who the murderer is from the many suspects present.
A wealthy judge coaxes the brilliant but eccentric neurological surgeon Dr. Vollin (Lugosi), who also has an obsessive penchant for Edgar Allen Poe, out of retirement to save the life of his daughter, a dancer crippled and brain damaged in an auto wreck. Vollin restores her completely, but also envisions her as his “Lenore,” and cooks up a scheme to kidnap the woman and torture and kill her fiance’ and father in his Poe-inspired dungeon. To do his dirty work, Vollin recruits a wanted criminal (Karloff), and turns him into a hideous monster to guarantee his subservience.
Sir Karell Borotyn appears to have been killed by Count Mora, a vampire believed to haunt the local village. Now his daughter Irena is the count’s next target. Enter Professor Zelen, an expert on vampires who’s sent in to prevent her death. At the same time, secrets are revealed surrounding the circumstances of Sir Karell’s death.
Investigating a series of murders in Chinatown, wise-guy reporter Jason Barton is captured by the megalomaniacal Mr. Wong, desperately trying to complete his collection of the twelve gold coins of Confucius, with which he will be able to acquire the power to become ruler of a large province in China.
The Black Magic cult of Ubasti, based on the isle of Lemuria, believes that Nadji, a princess of Egypt, is a reincarnation of their long-dead goddess, Ossana, and intend to sacrifice Nadji so that Ossana may be resurrected. Nadji has taken refuge at the California home of Frank Chandler, an American raised in the east and possessed of White Magical powers, who calls himself “Chandu”. Vindhyan, high priest of the cult’s California outpost, learns of this and ultimately succeeds in placing her in a trance which Chandu cannot easily break, propelling him to move her to safety, choosing the port of Suva in the South Seas. There, aided by his sister Dorothy, nephew Bob and niece Betty, Chandu is able to revive her and deal with Vindhyan, only to have the evil Voice of Ubasti, highest of the high priests, spirit her to Lemuria through the magic Circle of Ola. Chandu, Dorothy, Bob and Betty set out in pursuit but end up shipwrecked on Lemuria itself, with his family also now held for sacrifice while Chandu is plunged into the endless maze of caverns beneath the evil Temple of Ubasti, shrouded from his own powers by the full forces of Black Magic.
During a horrific storm at sea, the crew realizes that there is a murderer among them who is killing them off one by one.
Honeymooning in Hungary, Joan and Peter Allison share their train compartment with Dr. Vitus Verdegast, a courtly but tragic man who is returning to the remains of the town he defended before becoming a prisoner of war for fifteen years. When their hotel-bound bus crashes in a mountain storm and Joan is injured, the travellers seek refuge in the home, built fortress-like upon the site of a bloody battlefield, of famed architect Hjalmar Poelzig. There, cat-phobic Verdegast learns his wife’s fate, grieves for his lost daughter, and must play a game of chess for Allison’s life.
The heirs to a family fortune are required to attend a seance at the spooky old family mansion. However, throughout the night members of the family are being killed off one by one.
A mysterious criminal known as The Whispering Shadow commits crimes by means of a gang he controls by television and radio rays. Jack Norton, whose brother was murdered by The Whispering Shadow, suspects that the eerie Professor Strang – whose ghostly wax museum contains figures far too lifelike – may be involved in the crimes.
After his ship goes down, Edward Parker is rescued at sea. Parker gets into a fight with Captain Davies of the Apia and the Captain tosses him overboard while making a delivery to the tiny tropical island of Dr. Moreau. Parker discovers that Moreau has good reason to be so secretive on his lonely island. The doctor is a whip-cracking task master to a growing population of his own gruesome human/animal experiments. He does have one prize result, Lota the beautiful panther woman. Parker’s fortunes for escape look up after his fiancée Ruth finds him with the help of fearless Captain Donohue. However, when Moreau’s tribe of near-humans rises up to rebel, no one is safe.