Nell Bowen, the protégé of Lord Mortimer, wants to help change the conditions of notorious St. Mary's of Bethlehem Asylum (Bedlam). Though she tries to reform Bedlam, the cruel Master Sims who runs it has her committed there, but ultimately, it's the lunatics who've taken over the asylum.

An Egyptologist returns from the dead to take revenge on those who have violated his tomb.

When a nobleman is murdered, a professor of the occult blames vampires, but not all is what it seems.

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 fiancé 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.

Mad scientist Dr. Henryk Savaard is obsessed with bringing the dead back to life. The police are alerted to Savaard's activities, however, and Savaard is arrested, convicted, and sentenced to hang. He vows revenge on the judge, jury, and district attorney. After the hanging, his assistant claims the corpse and uses Savaard's technique to bring the doctor back to life. Now the mad scientist can seek sweet revenge on his perceived enemies

A wealthy industrialist hires the renowned hoax-buster Phillip Knight to prove that an island he plans to develop isn't voodoo cursed. However, arriving on the island, Knight soon realizes that voodoo does exist when he discovers man-eating plants and a tribe of natives with bizarre powers.

A gang of racketeers frames down-on-his-luck John Ellman for murder. After a trial finds him guilty, evidence is brought forth proving his innocence, but it is too late and he is executed anyway. A doctor sees an opportunity to use an experimental procedure to restore him to life but is that entirely possible? ....Or desirable?

In 19th-century Paris, the maniacal Dr. Mirakle abducts young women and injects them with ape blood in an attempt to prove ape-human kinship. He constantly meets failure as the abducted women die. Medical student Pierre Dupin discovers what Mirakle is doing too late to prevent the abduction of his girlfriend Camille. Now he desperately tries to enlist the help of the police to get her back.

A writer investigating the execution of a serial killer known as "The Haymarket Strangler" 20 years previously begins to suspect that the wrong man might have been hanged. However, when he picks up a scalpel used by the murderer, he finds himself possessed by the killer's spirit and begins to commit similar murders.

Rumours abound about what may go on at a creepy mansion just out of town. The house is owned by Dr. Eric Vornoff who is conducting experiments to turn people into super-beings through the use of atomic power. Reporter Janet Lawton decides to look into what is going there and its possible connection to men that have disappeared in the area. When Vornoff takes her prisoner, he has definite plans for her.

Rumours abound about what may go on at a creepy mansion just out of town. The house is owned by Dr. Eric Vornoff who is conducting experiments to turn people into super-beings through the use of atomic power. Reporter Janet Lawton decides to look into what is going there and its possible connection to men that have disappeared in the area. When Vornoff takes her prisoner, he has definite plans for her.

A ruthless doctor and his young prize student find themselves continually harassed by their murderous supplier of illegal cadavers.

A scientist becomes murderous after discovering, and being exposed to the radiation of, a powerful new element called Radium X.

From a slab in the morgue, a dead young woman tells the bizarre tale of how she got there, through a maze of murder involving a hypnotist, a midget and a mysterious figure in a green mask.

When an errant bomb unearths the coffin of a vampire during the London Blitz, a gravedigger unknowingly reanimates the monster by removing the stake from his heart.

A young man turns to a witch doctor to lure the woman he loves away from her fiancé, but instead turns her into a zombie slave.

A young French soldier cut off from his unit is beguiled by a mysterious woman, whom he learns is the wife of the local Baron - and that she seemingly died twenty years earlier.

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 travelers 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 the Allisons' lives.

The town's leading citizen becomes a homicidal maniac after his wife deserts him.

Dr. Thomas Bolton fights for the use of anesthetic in surgery and uses himself as a guinea pig, but soon finds himself addicted.