An overweight lab technician with low self esteem, brought on by his dominant mother, becomes a serial killer of female nurses.

Infamous burglar “The Bat” commits a daring jewelry theft despite heavy police presence. Soon after, a bank theft occurs, which may be the work of the criminal as well. Meanwhile, Cornelia Van Gorder has various people arrive at her old mansion, including her niece, Dale, a bank employee, and police detective Anderson. When guests start turning up dead, Cornelia begins to suspect that The Bat may be lurking around the estate. Hybrid horror, mystery, comedy

A singing ranch foreman (Roy Rogers) and his friend (George “Gabby” Hayes) urge a chorus-girl heiress (Dale Evans) not to sell the property.