Do you need to refresh your memory of the events of The Running Grave before reading The Hallmarked Man?
Spoiler warning: This page doesn’t name the killer, but it includes a summary of the case and gives full details of Strike and Robin’s relationship throughout this book.

Synopsis
The book opens with a collection of letters and other documents concerning the Universal Humanitarian Church and two of its members – Will Edensor and Kevin Pirbright. Will has left his former life behind and entered the church to the dismay of his parents, Colin and Sally Edensor. Kevin has left the church after growing up in one of its centres – Chapman Farm in Norfolk – and wants to expose what he saw and experienced there. The documents show that Colin Edensor assisted Kevin while he wrote an exposé of the UHC’s activities, in the hope that when published it might help extract Will from the church and bring him home.
Strike and Robin attend, as godparents, the christening of Benji, Nick and Ilsa Herbert’s much longed-for baby. Robin is accompanied by her boyfriend of eight months, Metropolitan Police DCI Ryan Murphy. Strike is miserable about this, as he has finally admitted to himself that he is in love with Robin. Robin is also in love with Strike, but refuses to allow herself to think that way about him, still certain that he would not want a permanent relationship with her, or any woman, and is thus determined to give things a go with Murphy.
Despite this, Strike and Robin’s professional partnership is thriving, and while waiting for the christening cake to be cut they discuss their new client, Sir Colin Edensor. Later, when they meet Colin, they learn that his wife has died of cancer and her last wish was for him to do everything he could to get Will out of the Universal Humanitarian Church, where he has now been for four years. Previous attempts to investigate the church by rival firm Patterson Inc have come to nothing.
Colin passes on his suspicions that, although it purports to be a charitable religious organisation, the UHC is in fact a money-making cult. As this is based in part on Kevin Pirbright’s written account, the detectives are keen to speak to Kevin, but Colin reveals he too is dead, shot in an apparently drug-related incident.
Robin makes the case to Strike that the best way to uncover useful information about the church’s apparently shady activities would be to send a member of the agency to infiltrate the church, and says she wants the job herself.
Research reveals that the UHC was founded by Jonathan Wace (known as Papa J) after the death of his first wife by drowning. Wace, who had a daughter, Abigail, with his first wife, then married Mazu, a young woman who had been part of the Aylmerton Community – a commune that occupied Chapman Farm before the UHC was created and from which the UHC grew. Later, Mazu’s elder daughter Daiyu drowned at the same beach as Wace’s first wife and became revered by the cult as ‘the Drowned Prophet’. Other prominent or useful deceased members of the church are also called prophets. Church members claim to see these prophets manifesting, as well as other unexplained phenomena. The church teaches that family relationships are to be eschewed, calling family members ‘flesh objects’ and that church members are to sleep with whoever asks them – they call this ‘spirit bonding’.
Strike is shocked to discover that the UHC’s Chapman Farm used to be occupied by the Aylmerton Community, the Norfolk commune to which Strike’s mother, Leda, took him and his younger sister Lucy when they were children; a place that Strike considers the worst of the many terrible places he lived as a child. Worrying that she may hear about the investigation and make the same connection, Strike tells Lucy what the Agency is doing and reveals the link to the commune. Lucy confesses for the first time that she was abused there. They have a frank conversation about their mother, which leads to Strike understanding Lucy a little better.
Having agreed that Robin will infiltrate the farm, Strike takes her to meet his sister Prudence, a therapist who is Johnny Rokeby’s other illegitimate child. Robin borrows some of her expensive clothes to appear wealthy enough to attract the attention of the UHC. She attends services at the UHC’s London temple, and is soon asked to a retreat at Chapman Farm.
Meanwhile, Charlotte, Strike’s ex-fiancée, is still trying to contact him, despite his attempts to cut all ties with her. She leaves drunken messages on the office answering machine, and later tracks Strike down to a pub in which he is interviewing an ex-member of the Church, where he reluctantly agrees to speak with her. She says that she has been diagnosed with breast cancer and tells Strike once again that she wants him back, but he rejects her and leaves.
Robin attends the week-long retreat and then allows herself to be recruited to the UHC. She endures many weeks at Chapman Farm during which she is subject to constant attempts to brainwash her, near-starvation rations and hard labour on the farm. The only communication she has with the agency is through exchanging weekly handwritten notes by leaving them in a plastic fake rock near the farm’s perimeter fence.
She gathers information on Jonathan and Mazu Wace, and discovers that Will Endensor has fathered a child with another church member. Towards the end of her stay, Robin reveals her identity to Will and tells him that his mother has died. It is clear from his reaction that Will did not know this.
Meanwhile, Strike finds out that Clive Littlejohn, a new subcontractor at the agency whom nobody much likes, used to work for the rival detective agency Patterson Inc. He confronts him, and Littlejohn admits that Patterson sent him into the agency as a plant. He had been blackmailing the agency’s office manager, Pat, over the fact that Pat has been pretending to Strike and Robin to be a decade younger than she is. Strike’s first impulse is to sack Littlejohn immediately, but he allows him to stay on when Littlejohn agrees to retrieve an old and mostly forgotten recording of an interview with Kevin Pirbright from Patterson Inc’s safe. When Strike has the material, he waits until Patterson has been arrested for planting illegal bugs and then sacks Littlejohn.
Whilst Strike is staying in Norfolk interviewing a witness to Daiyu Wace’s drowning, he hears the news that Charlotte has taken her own life. He drives to St John the Baptist Church which he remembers seeing from the commune when he was a child. Sitting in the church, he thinks about his relationships with Charlotte, his mother and Robin and realises ‘I want a good person for a change… I’m sick of filth and mess and scenes. I want something different.’
The Waces and other church members are becoming suspicious of Robin. Robin is sent to see Wace and he gropes her. Later, during ‘the Manifestation of the Drowned Prophet’ she is made to step into a pool and is then prevented from surfacing. As she runs out of air, believing she will drown, the last thing that crosses her mind is an image of Strike in the Landrover. After she is pulled from the pool she is taken to the basement of the farm house, where she is interrogated by the Waces and then tortured by being locked in a box in a kneeling position for hours. When she is released, she is tasked with looking after Jacob, a disabled child who is being starved to death by the UHC.
Meanwhile, Lucy calls Strike in distress and informs him that their widowed Uncle Ted, who has just been diagnosed with dementia, has gone missing. He is found safe, but Lucy and Strike agree that he cannot continue to live alone in Cornwall.
Agency subcontractor Dev Shah arrives at the farm to collect the weekly report from Robin but the plastic rock is missing and there is no note. Worried, Strike heads to Aylmerton. He arrives in the area and checks himself into a guest cabin at a nearby hotel. After dark, he drives to the perimeter fence to wait for Robin, who by now has been away for nearly four months.
As Strike arrives, Robin is struck by the realisation that she ‘knows’ that he is there. Upon being told that she must ‘spirit bond’ with Taio Wace, Mazu and Jonathan Wace’s son, she runs, chased by Taio. Strike sees her coming through the trees; he lifts her over the wall and strikes Taio with a heavy pair of wire cutters before speeding away with Robin back to the hotel. Robin cries with fear and relief in Strike’s arms.
Robin tells Strike about the dying child Jacob, and they call the local police who come and interview her. That night, Strike and Robin share the only available bed, holding hands for a few minutes before they fall asleep.
They head back to London. Ryan has been away visiting his sister in Spain, but when he returns, he tells Robin that he loves her. She automatically says the same back to him, and immediately has doubts about whether this is true.
As Strike and Robin continue to interview witnesses and investigate Daiyu’s death, they also begin to doubt Kevin’s death was drug-related. Will, along with his daughter Qing, escapes from the UHC and finds his way to the office. Will is on a kamikaze mission – he wants to find Qing’s mother (who has also disappeared from Chapman Farm) and hand himself over to the police. He refuses to make contact with his family and believes the Drowned Prophet will pursue and kill him as an apostate. Fearing he will flee, Strike and Robin reassure him that they will not attempt to reunite him with his father and will help him. Pat offers to take them to her house and she looks after them there.
On hearing that his son is no longer in the UHC, Colin agrees to be patient and to fund a limited investigation by the Agency to find out how Daiyu Wace died, in the hope that this will debunk the accepted account of her death, destroy her status as the church’s most important prophet and help Will overcome his delusions.
Later, at the office, Robin believes she is being watched from the street. She decides to spend the night on the office sofa rather than risk leaving. Robin and Ryan subsequently argue about this, as Ryan suspects that she slept in Strike’s flat rather than the office.
Robin meets up with Strike’s sister Prudence, and talks her into persuading her ex-UHC client, Flora, to meet with Will in an effort to help them both. Flora agrees, and they meet at Prudence’s house. Robin debunks the ‘supernatural’ events that they both believe that they have witnessed by telling them how they were faked. Flora opens up, telling them that the UHC have buried bodies at the farm, and that Wace is raping gay and mentally ill women to ‘cure’ them. She also reveals that the church is trafficking the babies that are born into the cult.
On the drive back to the office, they are followed by someone who shoots at them, smashing the windscreen and hitting the boot. Robin drives them to safety. After being interviewed by the police about this incident, Strike and Robin take a McDonald’s back to the office and make headway in the case. A few days later they meet with all their police contacts in the basement room of the Flying Horse. They outline all the evidence they have against the UHC in an attempt to force the police to make arrests. The police subsequently make raids on the UHC’s Birmingham centre and Chapman Farm.
Upon hearing about the raids, Robin goes to the UHC temple in Rupert Court where she confronts church members. Strike reveals Daiyu’s and Kevin’s killer and Ryan Murphy makes the arrest.
A couple of weeks after the case is wrapped up, Strike has lunch with Charlotte’s sister, Amelia, and they talk about the suicide note she left, which Amelia has destroyed.
On his return to the office, he finds Robin there waiting for Murphy to come and pick her up for a weekend away. He asks her into the inner office, where he tells her about his meeting with Amelia. Robin is reluctant to ask how Strike now feels about Charlotte, but Strike decides that, with a marriage proposal from Murphy perhaps imminent, he needs to speak up.
He confirms that he no longer loves Charlotte and his love was perhaps always based on wishful thinking. Alluding to Charlotte’s last letter, he suggests Charlotte would have claimed in it that she knew he was in love with Robin. As a confused and shocked Robin leaves with Murphy, Strike reflects that he may have done a foolish thing, but that it is well past time he took steps towards securing his own happiness.