Mild-mannered chemist Alvin Atterbury chafes under the constant criticism by his boss at a perfume factory. In response to being removed from an important experiment, Atterbury begins spending more time with attractive co-worker Myrna Duchane. At home Atterbury endures constant nagging from his wife, who begins to fear her husband may be planning to run away to Mexico with Myrna. The Atterbury's neighbor, elderly Mrs. Lazlo, grows concerned when she hears the couple arguing, punctuated one night by an unexplained scream. Soon after, Mrs. Lazlo notices that Mrs. Atterbury has disappeared. Unknown to Atterbury, his wife has rented their spare room to a young law student, Judy Carlton, who turns up at the house prepared to move in. When Atterbury initially refuses to allow her inside, a frustrated Judy seeks the help of Sheriff Cantrick and Atterbury reluctantly gives her access to the room. Perplexed by Atterbury's secretive behavior, Judy soon notices the chemist's nightly visits to the cellar, which are followed by strange sounds. Upon seeing Atterbury placing strange packages from the cellar in the freezer, Judy decides to investigate. In the cellar, Judy is horrified to discover what appears to be parts of a body, but before she can report her findings, she hears Atterbury returning with Myrna. Petrified, Judy screams, attracting the attention of Mrs. Lazlo, who summons Cantrick. Under the sheriff's questioning, Atterbury explains that he and Myrna have been working on their own experiment to develop a musk perfume, using the remains of a South American jungle animal, and are planning to sell the formula to a rival Mexican manufacturer. Just after they finish their account, Mrs. Atterbury returns and she and her husband admit that she is an alcoholic and has just spent a few days in a sanitarium for a rest cure. A few days later, Mrs. Lazlo calls, only to learn that Mrs. Atterbury is again out of town. After her departure, Atterbury returns to the cellar where he begins dismembering a mysterious object.