The bizarre death of Sir Paul Berowne has brought his family's problem out into the open as Dalgliesh questions the household to try and determine whether it was murder or suicide.

The death of Theresa Nolan, a nurse in the Berowne household, causes Dalgliesh's investigations to move closer to the family. Berowne's mother, Lady Ursula, now chooses to reveal a secret which she has been keeping for her son.

Dalgliesh traces Paul Berowne's mistress but he suspects that she is hiding the truth.