Buffy comes home one night to find her mother kissing a strange man. He is introduced as ted, and he and Joyce have been seeing each other for some time. Buffy is leery of this new man in her mother's life. Xander and Willow disagree - sure he talks like a '50's sitcom character, but he's a magnificent cook, and her mother seems happy. But Buffy is not convinced, especially after he threatens her during a miniature golf game when the pair of them are out of sight of the others.
When Buffy returns from a night of slaying, she finds Ted in her bedroom, having gone through her diary. She is justifiably angry at the invasion of her privacy, but her attempts to complain result in his striking her. That gives her the excuse she needs to wallop him - so much so that he falls down the stairs, dead. The police question her, and let her go for the time being.
Buffy is devastated at this abuse of her powers as the Slayer. But then, Willow, Xander and Cordelia dig deeper into Ted's life - finding drugs in his cookies, marriages dating to 1957, and odd things in his closet - Ted himself turns up alive at the Summers' house. He turns out to be a robot, and what's in his closet are his four previous wives...