The plot of Get Lost! concerns the disappearance of Jim Threadgold (Brian Southwood), husband of English teacher Judy Threadgold (Turner). Aided by her colleague, woodwork teacher Neville Keaton (Armstrong), Judy sets out to find out what has happened to her husband. Judy and Neville soon discover the existence of a secret organisation dedicated to assisting people who want to escape the mundanity of their lives and families and just disappear. Although Judy eventually finds her missing husband, she is none too enthusiastic about taking him back and allows him to seek a new life running a fish and chip shop. Her adversarial relationship with Neville blossoms into a love affair.