Joe is an entrepreneur. A man comes to his house to demonstrate a device he has invented. He wants Joe to invest in it. To Joe's amazement, the device works. It turns his conservative wife and virginal stepdaughter into a couple of horny zombies. Later, he and his stepson use it on the two women again. A big taboo orgy follows! Joe has a new neighbor. She's a young and bubbly blonde named Summer. With his wife away visiting relatives, Joe is home alone for the week. Summer takes advantage of that fact to come over and flirt with him as often as possible. Her ploys include brushing up against him, wearing skimpy clothes, and sunbathing topless. Eventually Joe gives into temptation. Up in his room, he and Summer enjoy a wild night of adulterous fucking.