An all-American family inherits a deceased uncle's house. John (Richard Benjamin) and Mary Hyatt (Paula Prentiss), together with daughter Debbie (Kari Michaelsen) and son Billy (Kevin Brando), move in, but Waldemar (Jeffrey Tambor), a vampire, and Yolanda (Nancy Lee Andrews), his wife, want desperately to get into the rundown house because it contains a book of evil.