Sir Paul Berowne - a prominent Government Minister - turns to his old friend Adam Dalgleish following a series of threatening letters delivered to his London home. The minister's wife is in an adulterous affair with a prominent surgeon and she makes no secret of it. Berowne's only daughter is involved in left-wing politics and rejects her conservative father. Adding to his woes, his own mother favoured her son who was killed in an IRA terrorist ambush over Paul. The informal investigation has barely began when Dalgliesh is faced with a series of bizarre deaths that turn the case into an urgent assignment.