Love

Scientists have identified the secret of long-lasting love and claim they can tell which marriages will make it. To test this, four couples - two on the brink of divorce and two newlyweds - go through a series of experiments to see how being out of love affects how they physically see their partner and how their physiological reactions to conflict threaten love. With the new understanding of each other's biochemical and psychological behaviour, the couples embark on a programme designed to rescue their relationships.