Keith, Anna and their son Peter are a close, loving family living in a smart suburban street of a provincial city. Anna is a typical middle-class housewife, filling her day with good works, until one day, when she finds a note that leads to a shattering discovery - her husband has been having an affair. Anna's intense shock at finding out Keith's secret is compounded when she arranges to meet his lover. When Steve arrives at the meeting place, Anna is forced to accept the fact that Keith has been leading a double life for the length of their marriage. Steve stresses the risk of AIDS and urges Anna to have an AIDS test. To show her what it can be like to live with the disease, he introduces her to Jim, who needs 24-hour care and has developed a realistic attitude towards his own death. When Keith leaves home suddenly, Anna is forced to tell her son about the threat of HIV, but Peter turns violently against her and runs away.

Jemma Redgrave is Gale Francombe, a woman trapped in a loveless marriage to a powerful, but wealthy man, so she conspires with her lover Adam,(Gary Mavers) to plot the perfect murder.