Commander Adam Dalgliesh is asked by a friend, Home Office Minister Sir Paul Berowne, to be aware correspondence of a personal nature he's received. He's not being blackmailed and so there's nothing to investigate per se and he only wants Adam to keep an eye on what's going on. Sir Paul's personal life is somewhat complicated. He lives in the shadow of his late brother Hugo and has little time for his wife Barbara who is having an affair with Stephen Lampart. She is now pregnant but insists that the child is his. He's fed up with it all and decides to chuck it all in. He's not only going to resign from the Cabinet and Parliament but has decided to cancel his investment in Lampart's medical clinic and sell the family home. While on an outing, one of the Berowne family servants, Diana Travers, drowns. At New Scotland Yard meanwhile, Dalgliesh is putting together a new squad and asks Inspector Kate Miskin to join the team. —garykmcd

Sir Paul Berowne gives his latest anonymous letter to Adam Dalgliesh and the next day visits Father Francis Barnes at St. Matthews Church in Paddington, requesting permission to spend one night alone in a spare room at his church. The next day, Sir Paul's body is found by Mrs. Wharton, a church volunteer, his throat slit. There was also a homeless man, Harry Mack, also dead in the room with him. Dalgliesh takes charge of the case and learns from Father Francis that he had only known Berowne for less than two weeks but had noticed something very peculiar at communion. Mack was a regular often seeking shelter at the church. Inspector Miskin looks into the death of Sir Paul's servant Diana Travers and they are surprised that the post-mortem was performed by the Special Branch pathologist. —garykmcd

Commander Dalgliesh and Insp. Miskin continue their interviews with those associated with the case. Gordon Halliwell, the family chauffeur, came to the Berowne family after serving with the deceased Hugo in the army. He freely admits that he and Sir Paul didn't along. Barbara Berowne's brother Dominic Swayne has an alibi. Dalgliesh also questions him about the death of the Berowne family's servant, Diana Travers, who drowned. Swayne says she wasn't an unemployed actress as she claimed. Berowne's daughter Sarah didn't get on with her father and were estranged owing to political differences and the way he treated her mother. The pathologist won't rule out the possibility of suicide though he tells Dalgliesh it's most likely murder. Teresa Nolan the nurse who looked after Sir Paul's mother, admits to him that she had an abortion a few weeks before, but refuses to identify the father. She is later found dead, an apparent suicide. —garykmcd

Berowne's daughter clearly has a secret that she has not shared with anyone except Ivor Garrett. Dalgliesh re-interviews Lady Berowne, Sir Paul's mother, and she lets it slip that he had a mistress. She is Carole Washburn who tells Dagliesh that Berowne had gone through a religious conversion. She refuses however to disclose anything else about their relationship other than they met at work and were always discreet. Dalgliesh visits the site where Diana Travers drowned and learns from the restaurant doorman, Henry, that Berowne was there the day of the drowning and was seen soaking wet. He also meets Millicent Gentle who, she says, was expecting him. Insp. Miskin meanwhile struggles with her own guilt over her grandmother who cannot live alone and who she wishes to put into a care home. —garykmcd

Millicent Gentle tells Dagliesh of the day Diana Travers died. Annoyed by the revelers on the water she had gone out and saw Sir Paul Berowne fighting with another man. He was soaking wet and she invited him back to her cottage to dry off. Berowne admitted the fight was about a woman and they spent about two hours talking. She also saw him on the day of his death when he came to visit but he had little to say and left quietly. Dalgliesh quickly determines that Berowne had fought with his brother-in-law Dominic Swayne who denies killing him. Dalgliesh is upset to learn that Travers was a Special Branch operative. Carole Washburn tells Miskin that nurse Teresa Nolan may have had information about Stephen Lampart's clinic. Insp. Miskin meanwhile rushes to the hospital when she learns her grandmother has been mugged. —garykmcd

Dalgliesh visits the church where Berowne was killed and is surprised when Father Francis finds a button in the offerings box. Emily Wharton thinks it must have been young Darren who put it there instead of the 10 pence she had given him to go and light a candle. The Berowne's cook, Miss Matlock, clearly recognizes the button but says she can't recall where she's seen it. Halliwell the chauffeur tells Dagliesh that he drove Sir Paul's mother to the church on the evening her son was killed. They also learn that someone else went to the church as well. Darren is lured to a secluded spot. Desperate to get away, the killer takes Miskin and her grandmother prisoner but tragedy ensues. —garykmcd