Hired to protect a beautiful but neurotic actress, Cordelia Gray soon becomes embroiled in a case as dangerous to her own life as it is mysterious.

Clarissa Lisle hopes to make a spectacular comeback in a production of The Duchess of Malfi, to be played in Ambrose Gorringe's sinister castle at Courcy Island. Cordelia is there to ensure her safety following the appearance of a number of poison-pen letters. But it soon becomes clear that all are in danger.