Sir Paul Berowne, a prominent minister, approaches his old friend Adam Dalgliesh after receiving a series of threatening letters at his London home. Berowne's wife is cheating on a prominent surgeon and she makes no secret of it. His only daughter is involved in left-wing politics and despises her conservative father. In addition, his brother, whom their mother loved more, was killed in an attack that was committed because of Paul's political work. The informal investigation has barely begun when Dalgliesh is faced with a series of bizarre deaths that make the case an urgent matter.