Middle-class suburbanites Larry and Kitty grow bored with their lives and respective marriages. Although each always found the other's manner grating, they fall in love when thrown together--without their spouses--on vacation. On returning home they try to break things off, only to grow closer. A holiday together will finally settle whether they should end their marriages.

When Chester accidentally memorises and destroys the only copy of a secret Russian formula for a new and improved rocket fuel, he and Harry are thrust into international intrigue, trying to stay alive while keeping the formula out of enemy hands.