Contemporary painter Hedley Shale is found murdered with two bullets in his home. Lying nearby is his secret lover, French model Francesca - bound and gagged by the black-hooded intruder who shot the artist and then escaped through the back garden. Shale's wife, Serena, steely editor of a national woman's magazine, would, by all laws of logic, appear to be the killer. But she was at work throughout the morning. So how could she have committed the crime?