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.

Piece by piece Dalgliesh is putting together the jigsaw of clues behinf Sir Paul Berowne's death.