Very spoilery. Also check out my review, my article on the ending and order of deaths, the episode 1 re-cap and episode 3 re-cap.
Dr Thomas’s funeral is held, with Bobby a pallbearer. The policeman doesn’t believe Bobby that it wasn’t suicide, despite the lack of a note, mentioning the death of John Savage — people may kill themselves when there seems no reason for it. Dr Thomas’s false leg has also disappeared.
Frankie collects her mother’s dress from the cleaner’s. She collects her chauffeur’s uniform too, as a plan is forming in her head.
Bobby takes the train to London, seeing in a newspaper a story about the death of John Savage. Frankie and her friend Dr George Arbuthnot appear in his compartment. She has pumped the local estate agents for information and discovered Roger Bassington-ffrench’s home address, Merroway Court in Staverley, Hampshire. She believes Roger killed Dr Thomas and Alex Pritchard, and wants to prove it.
Her basic plan, later finessed with assistance from Bobby, Knocker and George, is to crash her car into Merroway Court’s perimeter wall, plead injury and stay at the house to recuperate, all the while investigating Roger and the other inhabitants there. Frankie goes to buy a car from Knocker and Bobby’s garage. In the event, Knocker guides the runaway car then jumps off, letting it crash into the Merroway Court gate wall. Frankie climbs in, covers herself in blood and pretends she was driving and is now concussed. George goes up to the house for help, pretending he was passing by, and backing up her claim to injury. Knocker and Bobby head off afterwards on a motorbike while George carries Frankie in to the house and deposits her on a day bed. George tells Sylvia Bassington-ffrench, the lady of the house, that Frankie should stay there for a couple of days. When Sylvia suggests a local doctor for a check up the next day, he tells her Frankie is a Christian Scientist so can’t do that.
George goes to the local inn, the Anglers Arms, to meet Bobby and Knocker. Bobby decides to stay there for a few days, to keep an eye on Frankie.
Snooping around her ground floor room, Frankie finds a gun in a drawer, and outside hears a crow-scarer go off (which sounds like a gun).
Bobby checks in. The room keyring has a brass fish on it, the same as the one he discovered in Alex Pritchard’s pocket. He also finds an Alan Carstairs listed in the visitors book and his address, a club in London.
Sylvia’s husband Henry Bassington-ffrench arrives home at Merroway Court, furious about his damaged wall.
Bobby questions the inn landlord, Mr Askew, about Alan Carstairs, claiming they are friends. He finds out the man was South African and left in the middle of the night without his luggage, which the landlord has by now sent on to the man’s club. He also tells Bobby about The Grange, the local big house that is now a sanatorium. “Not a happy place,” says the landlord.
Bobby goes back to Merroway Court that night and sees Frankie through the window, then spies a young woman in an evening dress in the grounds. It’s the woman from the original photo that Bobby found on Alan Pritchard’s body. Roger Bassington-ffrench, Henry’s brother, arrives home at Merroway Court.
Bobby’s father finds Bowler Hat Man playing the organ in the Marchmont village church. He’s subtly threatened, until the local policeman walks in, and the man disappears.
At Merroway Court, Frankie is getting up and realises she has forgotten where she’d put her fake wound; she doesn’t know which side of her forehead her plaster should go on. Frankie joins the family for breakfast and meets Roger. Henry is very jittery, annoyed by Roger’s spoon-tapping.
Bobby sees the Caymans having breakfast at the Anglers Arms. They leave without paying, and he follows them on his motorbike until they drive into The Grange.
Roger Bassington-ffrench is charming and urbane, and suspects Frankie is looking for something. He’s not taken in by her car crash story, but tells her he’s glad she’s there. She finds Sylvia crying: her husband Henry is a morphia addict, with a package of the drug delivered twice a week.
Bowler Hat Man appears in Knocker’s car showroom, though Knocker won’t tell him where Bobby is and sends the man away. From the way Knocker speaks about Bobby, it sounds is as if saved Knocker from the sea when they were both in the Navy; it’s a warning that he will protect Bobby. Knocker answers a call from Frankie, and the man returns, beating Knocker up. He’s found on the floor by Lord Marcham’s butler, who has turned up with the family Lagonda (which Bobby is meant to drive down to Staverley).
Sylvia tells Roger and Frankie that Dr Nicholson, owner of The Grange, and his wife Moira will come the next day and observe Henry, with a view to him being admitted.
Moira visits Bobby at his hotel, telling him she believes her husband is mentally ill. She claims no knowledge of an Alan Carstairs. The butler arrives with the Lagonda and a chauffeur’s uniform from Frankie.
That night, Frankie finds Sylvia and Henry dancing outside on the terrace. Henry asks Frankie to dance, and he tells her she “lies very well” (he’s referring to her saying he’s a good dancer). He also tells her Sylvia wants to put him away so he can have electric shock treatment, something they do to pigs to dull their senses so they are easier to kill.
Bobby, going by the name of “Steve”, calls the house and speaks to Frankie, telling her the dead man was Alan Carstairs, and he’d been in Staverley a few weeks’ earlier. He wants her to leave but she refuses.
The next morning he comes to the house and he and Frankie go through what they know and who can be ruled out. Frankie doesn’t think Roger is capable of murder. Roger was also back in Staverley when Dr Thomas died. Bobby was drugged with morphia, and Henry has regular supplies. Bobby has also met the woman in the photo (Moira Nicholson), who claims her husband is very dangerous. “What if we’re in the wrong house? Maybe I should have crashed into The Grange,” suggests Frankie. Bobby points out they still don’t know the identity of Evans, “they”, and what “they” didn’t ask about.
The two investigate Merroway Court, including Roger’s room, where they find house details for a place in Marchbolt. Frankie hears music playing and goes to investigate, finding an angry-looking Henry. Bobby also finds agent details for the Mill House, a riverside rental house in Berkshire.
Dr Nicholson and his wife Moira arrive for lunch, as Sylvia, Roger and Tommy return from church. Bobby is still in Roger’s room and Roger is heading back up there, so Frankie invites him for a drive there and then. He goes into his room, but doesn’t see Bobby, who is already somehow outside, with the car. Sylvia calls them back in, and they meet Dr Nicholson and his wife. Dr Nicholson states clearly that he does not think Frankie’s accident was an accident.