Released 13 December 1940, The Devil Bat was the very first horror film made by then-new Poverty Row studio Producers Releasing Corporation (which went on to make many quality films which earned high praise). This film was also part of Béla Lugosi’s comeback after his career had gone into decline (due to new Universal management and the U.K.’s ban on horror films).
Dr. Paul Carruthers (Lugosi) of Heathville is a beloved citizen and respected research scientist for Heath-Morton Cosmetics, Ltd. Little do the villagers know what dark, twisted secrets are lurking in his hidden lab overlooking Martin Heath’s impressive estate.
Dr. Carruthers is keeping a bat whom he greatly increased in size, and training it to attack anyone wearing his Oriental aftershave.
Dr. Carruthers is invited to a party at the Heath estate, but begs off attending because he’s working so hard on a new formula. Everyone is disappointed he’s a no-show, since they planned to surprise him with a $5,000 bonus check.
Roy Heath visits him to deliver the check in person, and is talked into trying out the new aftershave. Dr. Carruthers tells him goodbye instead of goodnight when he takes his leave.
Instead of seeing that check as a generous gift, Dr. Carruthers feels insulted. He’s worked so hard for that company and helped to make them rich, while they expect him to be grateful with peanuts in return. Enraged, he sends his bat into the night.
The bat swoops from the sky to attack Roy when he arrives home, as his sister Mary (Suzanne Kaaren) and her friend Don Morton (the co-founder’s son) look on in horror. Dr. Carruthers is called to the scene and pronounces it a hopeless case.
The local newspaper immediately jumps on this mysterious unsolved murder, with young reporter Johnny Layton (Dave O’Brien) and cameraman One Shot McGuire (Donald Kerr) leading the investigation. Despite their boss Joe’s natural skepticism, they believe Dr. Carruthers’s theory that the culprit was a bat.
Tommy Heath tests the aftershave next, and once again Dr. Carruthers tells him goodbye instead of goodnight before releasing the giant bat. In full view of a horrified Mary, Johnny, and McGuire, Tommy is attacked and killed.
All of Heathville now lives in terror of the Devil Bat. This fear increases when the bat attacks a third victim, Don Morton.
All three victims had the same aftershave, leading to suspicions that a disgruntled factory employee is the one offing people in the Heath and Morton families.
Johnny and McGuire are fired when it comes out the Devil Bat they photographed was made in Japan, but that doesn’t deter them in the least. They continue the investigation on their own.
Dr. Carruthers cordially cooperates with the police chief and Johnny when they question him about the ingredients of his aftershave and why the three victims were wearing it. The chief begs off trying the aftershave, for fear his wife would suspect another woman, but Johnny takes a sample to use later. Yet again, Dr. Carruthers says goodbye instead of goodnight.
While Johnny and McGuire are waiting for the bat that night, their big chance arrives. They shoot it dead, a development which is immediately the subject of many news stories.
Not one to be deterred easily, Dr. Carruthers gets another bat. His next victim, co-founder Henry Morton, takes more convincing than the others to put the aftershave on his face then and there instead of waiting till morning.
Dr. Carruthers is enraged when Henry reminds him he sold his first formula for only $10,000 and gave up his partnership stake, while the company has made over a million dollars. He once more says goodbye instead of goodnight.
With the second Devil Bat on the loose, Heathville once again lives in terror. Now Johnny, who’s been rehired, makes his move to prove once and for all who’s really behind these attacks.