THE DEVIL BAT (1940). Colorized

THE DEVIL BAT is a 1940 was an American horror film produced by Producers Releasing Corporation (PRC) and directed by Jean Yarborough. The film stars Bela Lugosi along with Suzanne Kaaren, Guy Usher, Yolande Mallott and the comic team of Dave O'Brien and Donald Kerr as the protagonists. It was the first horror film from PRC.

PLOT:
"All Heathville loved Dr. Paul Carruthers...the doctor found time to conduct certain private experiments — weird, terrifying experiments."

Dr. Paul Carruthers (Bela Lugosi), a chemist and physician in the small town of Heathville, is offered a $5,000 bonus from his employers for his contributions to the company, a pittance compared to the million dollars in income the company earned from his work. (His employers argue that he took a buyout early in the company's history instead of retaining his partnership stake.) Embittered and insulted, he seeks revenge and develops a system in which ordinary bats are enlarged to massive size, training them to be drawn to a new, pungent aftershave he is testing. He cleverly distributes the lotion to his enemies as a "test" product.

Once they have applied the lotion, the chemist then releases his Devil Bats in the night, targeting the families of his employer's owners. The bats succeed in attacking and killing one of the owners and two of his sons. A hot shot reporter from the Chicago Register, Johnny Layton (Dave O'Brien) gets assigned by his editor (Arthur Q. Bryan) to cover and help solve the murders. He and his bumbling photographer "One-Shot" McGuire (Donald Kerr) begin to unwind the mystery with some comic sidelights.

In the climactic closing scene, Layton dumps a sample of the aftershave on Carruthers, leading the bat to attack and kill its own master. Mary, the last surviving member of her family, runs into Johnny's arms.