The plot concerns the murder of a West End stage actress during her 50th birthday party, and continues Marsh's fascination with the theatre and with acting.

Indulged, egocentric Mary Bellamy, West End theatre star of light 'well-made' comedies rather than the grittier new style of Beckett, Osborne or Pinter, is celebrating her 50th birthday at her London home.

These include: her wealthy businessman husband, an ageing former suitor, her adopted son (in whose first play, a light comedy, Mary starred), her former nanny and former dresser (two vinegary rivals) and three theatre colleagues - Mary's actress friend Pinky Cavendish, her favoured costume designer Bertie Saracen and the formidable theatre director.

Matters come to a head at the birthday party itself, attended by the press and cream of London theatre, when Mary turns viciously upon her adopted son and the unknown young actress he loves and for whom he has written his new play.

Mary storms up to her bedroom and is found, dying horribly after spraying herself from a perfume-bottle someone has filled with toxic 'Slaypest' for potted plants.