In a small town, a brilliant but wronged chemist embarks on a dark path of revenge against those he believes have betrayed him. Utilizing his expertise in science, he genetically engineers a giant bat to attack anyone wearing a certain aftershave lotion he has also developed. This lotion is his method of marking his victims, who are unknowingly lured to their doom. The chemist gives away bottles of this special lotion to his targets under the guise of a friendly gesture, not revealing the deadly intentions behind his actions. His plan is set into motion with cold precision as he watches the chaos unfold, driven by a deep-seated desire for vengeance against his employers whom he accuses of stealing his formulas and profiting from his work without giving him due credit.

Meanwhile, a determined and curious reporter arrives in town to investigate the strange and deadly attacks that have left the community in fear. Suspicions arise as the reporter delves deeper into the mystery, piecing together the connection between the chemist, his unique lotion, and the horrific bat attacks. With the aid of the chemist's beautiful daughter, who is unaware of her father's sinister activities, the reporter starts to close in on the truth. They find themselves in a race against time to stop the chemist before more lives are lost to his revengeful scheme, uncovering a web of deceit, betrayal, and madness along the way.