Working in Dr. Cranley's laboratory, scientist Jack Griffin was always given the latitude to conduct some of his own experiments. His sudden departure, however, has Cranley's daughter Flora worried about him. Griffin has taken a room at the nearby Lion's Head Inn, hoping to reverse an experiment he conducted on himself that made him invisible. But the experimental drug has also warped his mind, making him aggressive and dangerous. He's prepared to do whatever it takes to restore his appearance.

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

A fugitive, dangerous madman reaches an English village where he confronts his former partner who left him for dead in the jungle after their discovery of a diamond mine. When the former partner also claims to have since lost the mine and all its wealth, which he took all for himself, and though the partmer is still living in a state of luxury , the madman takes up an offer from a crazed scientist to make him invisible, something the scientist has already done with experimental animals, so that he can take revenge.

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.

The Invisible Man's grandson uses his secret formula to spy on Nazi Germany in this comedy-thriller.