Strike (Tom Burke) is told by Brian (Billy Boyle) that Mollie was everything to him and can't believe Dennis Creed (Kenneth Cranham) killed her. He also suspects that he killed Margot and Kara too. However Robin (Holliday Grainger) tells him Kara was killed by Ricci. Brian says no one will know what happened to his daughter, Louise and with Creed in prison there's no way to find out. Creed was writing his memoirs and a guard at the prison gave him info on Margot. Brian wrote to Creed and he wrote a letter back, he's into games. His letter reads in the first sentence of each line: "your daughter cried for her mummy before she died." Strike would be able to speak with Creed as he's well known and he pays them to see what happened to his daughter. Robin agrees to help him and offers to work in her spare time without taking his money. Strike warns her that Creed won't help. Robin wants to help at least one of them and can't put this behind her. After everything she's been through of course she won't let it go.
At the pub, Strike shows her evidence of photos Pat (Ruth Sheen) gave him. Lucy calls him to say his aunt probably won't last til Christmas. Strike looks through his photos and gets an email invite from Johnny Rokesby. As Strike feeds a homeless man, Pat tells him she called the council about the curry found outside. He doesn't tell her and gets Sam (Jack Greenlees) to call Paul. Robin asks Izzy (Christina Cole) to see of she can see a prisoner at Broadmoor. Strike is called by Beth who tells him Samhain said Margot was killed by Nico Ricci. Robin cooks for Max's dinner party and her brother is coming too. Strike tells Robin of the phone box and she says there was a delivery van that was speeding in the area but kept the driver quiet so as to avoid police. Creed wasn't in the van. Also Strike says it didn't fit Creed's MO as he would spike his victim's drinks.
Strike reviews Ruby's interview from 1975 and she was near the phonebox and saw two women together and she thought they had been drinking by their behaviour. Robin looks at the article and says it was a woman and her daughter but Strike adds it was the other way round as Fiona was taller. It could have been Margot and Creed, as Creed would've been shorter than her, but it is unlikely. Paul agrees to talk with Strike. Johnny calls Strike and he opens up that he has cancer so time is running out. Heck not another one dying. Strike tells him to leave him alone. Strike drinks and talks about being a soldier and gets into an altercation with Robin's brother's girlfriend, Courtney (Maia Tamrakar). Robin tries to diffuse the situation, but Johnny begins talking about rape and Strike apologizes to Robin and leaves. She calls him out on it and he apologizes but it isn't what she wants to hear. Next morning he's at the office with Lucy. They both head to Cornwall and run into flooded streets. Finally making a breakthrough in a boat.
Robin calls and offers sympathy for Joan's passing and Creed will only speak with Strike. He agrees. Anna knows her father tried to find Margot and she's run out of money to pay him more. He agrees to lower his rate. As Robin meets with Matthew and only wants her parents' deposit back for the house. As she later meets Brian with Strike, he tells them about Creed. He was into Aleistair Crowley and he attended satanic rituals with women. The notebook mentions Schmidt explaining all. As they play with Tarot cards Robin picks the Lovers card and conceals it from Strike. Strike meets with Creed who thinks men like him are necessary in society and they get onto the subject of Crowley. Brian tried to get to Creed using star signs. Strike tells him his doctors don't believe Creed is sane and he talks of poisoning women. As well as saying his client is Margot's daughter. Creed wants to return to Belmarsh and write his book. He admits to killing Louise after he saw her in her uniform and he took her necklace.
Strike doesn't believe Creed killed Margot or Louise and Creed mentions M54 where Louise's body will be found. Which he and Robin try to work out. Strike discovers it's a star in the Saggitarius constellation. Robin thinks Louise could've been at the Archer Hotel and Strike speaks with George Layborn who talks of a skeleton being found. Strikes recalls Creed mentioning being born under the 13th sign. Robin informs him of Schmidt finding a 13th sign under the 14th star system. This means peoples' stars change and Stephen Douthwaite would become Capricorn and the notebook says Capricorn killed Julie B. She was a holiday rep at Baxton's. She was found in the pool and Steve worked there but left afterwards. Robin surmizes he killed Margot and then his girlfriend was found dead.
Lots of jumping around in this episode with coming up with theories that some prove viable and others don't. Strike and his moment with the homeless man stands out as does his getting drunk. It just speaks othois character and fouling things up at the dinner party. Deeply hurt by Joan's passing as well as Johnny revealing his diagnosis. Yet he doesn't have anything but coldness towards Johnny. Trying to keep churning out who really killed Margot to the end!