Best Science Fiction Movies of 1940

Four explorers are summoned to Peru by the brilliant physicist Dr Thorkel. They discover a rich source of radium and a half-mad Thorkel who shrinks them down to one-fifth their normal size when they threaten to stop his unorthodox experimentation.

The owner of a coal mining operation, falsely imprisoned for fratricide, takes a drug to make him invisible, despite its side effect: gradual madness.

University professor George Kingsley is struck by gangsters while crossing the street, leaving him with brain damage and one of the gangsters, Cannon, paralyzed. Kingsley's friend Dr. Sovac attends to both men, and when Cannon offers him a reward for aiding his recovery, Kovac transplants part of Cannon's brain into the dying Kingsley's skull, creating a dual personality.

Kitty Carroll, an attractive store model, volunteers to become a test subject for a machine that will make her invisible so that she can use her invisibility to exact revenge on her ex-boss.

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.

Dr. Leon Kravaal develops a potential cure for cancer, which involves freezing the patient. But an experiment goes awry when authorities believe Kravaal has killed a patient. Kravaal freezes the officials, along with himself. Years later, they are discovered and revived in hopes that Kravaal can indeed complete his cure. But human greed and weakness compound to disrupt the project.

A physician on death row for a mercy killing is allowed to experiment on a serum using a criminals' blood, but secretly tests it on himself. He gets a pardon, but finds out he's become a Jekyll-&-Hyde.

The nefarious Dr. Fu Manchu searches for the keys to the tomb of Genghis Khan, in order to fulfill a prophecy that will enable him to conquer the world. His nemesis, Dr. Nayland Smith, and his associates fight to keep the evil doctor from getting his hands on the keys. In 1943, the serial that was edited together into a feature movie also called Drums of Fu Manchu.

A newspaper publisher and his Korean servant fight crime as vigilantes who pose as a notorious masked gangster and his aide.