What happens
The finale brings the two investigations to their final explanations. Susan still needs to connect Cecily’s reading of Atticus Pünd Takes the Case with the earlier conviction at Branlow Hall. The novel has given her a crowded collection of names, props, echoes and apparent coincidences; she must decide which of them actually reveal the author’s intention. A visit to Stefan offers a chance to hear from the person whose life has been most directly shaped by the original investigation.
Pünd, meanwhile, must explain his unsettling claim about John Spencer’s death. His answer calls for a second look at the people who have been helping him, the arrangements that brought him to the case and the distractions during its most crucial moments. The case has never been only about Melissa’s last evening.
For Susan, finishing also means deciding how she wants to live with Andreas after the investigation. The episode offers the pleasure of a traditional gathering of suspects, but its most interesting question is personal: what responsibility belongs to somebody who recognised a dangerous truth and chose to turn it into a puzzle?
Ending explained (full spoilers)
Moonflower Murders ending explained
Aiden MacNeil killed Frank Parris and Cecily, while Madeline Cain killed John Spencer in Pünd’s fictional investigation. Susan solves the modern case by understanding who Alan Conway meant by Leo. Pünd’s claim that he killed John is an expression of responsibility: he brought Madeline into the investigation, but she committed the murder.
Susan’s visit to Stefan helps her question the account that put him in prison. He remembers feeling overwhelmed after little wine, suggesting he was drugged, and hesitates over his meeting in the woods. Conway’s dedication, Aiden’s birthday and a tattoo then fit together. Leo was Aiden’s name when he worked as an escort. The supposed Australian connection is misleading because Melbourne can also refer to the town in Derbyshire.
Frank recognised Aiden at Branlow Hall and used that knowledge to coerce him before the wedding. Aiden decided to kill Frank and put the blame on Stefan. He drugged Stefan, used his clothing and toolbox, and injured Chase with the brooch so that Derek would come upstairs and encounter the misleading trail. After the murder, he planted money and blood in Stefan’s room. The missing fountain pen belongs to this carefully arranged false account.
Cecily’s disappearance follows from her reading. She understood the dedication and recognised what Leo meant. Aiden discovered that she knew, and killed her to protect himself. Susan also explains that Cecily, rather than Lisa, was Stefan’s partner in the woods, and that Roxana is Stefan’s daughter. Those relationships help untangle the family’s secrets, but they do not make Stefan the murderer. Aiden is arrested after Susan lays out the explanation at Branlow Hall.
Pünd’s resolution turns on someone he trusted. Madeline was an obsessive admirer of Melissa and hired an actor to pose as the American agent who brought Pünd into the case. Her apparent fainting spell helped conceal a fan letter that could expose her involvement. When John confessed, she killed him during the distraction at the window. Eric, outside listening, was frightened about his own conduct rather than responsible for that killing. Madeline is arrested.
The final connection is a word game: Madeline Cain and Aiden MacNeil are anagrams. Television leaves that last recognition to the audience. It links the two murderers without making the fictional events a literal account of the real ones. Conway knew how to conceal dangerous knowledge in a puzzle, and Susan has had to turn his literary tricks back into an explanation of what happened to people.
For Susan, the ending also answers the question of life after the investigation. She and Andreas can return to Crete, with freelance editing offering a way to retain the work she loves. Pünd has finished his case and confronted the consequences of trusting Madeline. Susan finishes hers with the possibility of keeping both her relationship and her professional life.
Sources: PBS episode 6 and transcript. Checked 19 October 2026.
How the book ending differs (book spoilers)
- The killers remain Aiden MacNeil, Leonard Collins and Madeline Cain in both versions.
- In the novel, Susan recognises the Madeline Cain/Aiden MacNeil anagram; television leaves that last recognition to the viewer.
- The book includes additional lion references, among them Melissa’s dog Kimba and Algernon’s Peugeot.
- The novel gives Aiden a final letter and a fatal encounter with a train after he escapes. Television ends his story with arrest.
Read or listen to Moonflower Murders
Moonflower Murders
Anthony Horowitz’s novel behind the television adaptation.
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Who’s in this episode
Susan Ryeland
Played by Lesley Manville. Susan brings the real-world accounts and Conway’s word games into one explanation.
Atticus Pünd
Played by Tim McMullan. Pünd identifies the second killer and confronts his own misplaced trust.
Aiden Macneil
Played by Will Tudor. Aiden must answer Susan’s reconstruction of the wedding weekend.
Andreas Patakis
Played by Alexandros Logothetis. Andreas supports Susan as she completes the case and considers her future.
Superintendent Locke
Played by Daniel Mays. Locke is present when the original conviction is challenged before the family.
Alan Conway
Played by Conleth Hill. A remembered editorial discussion returns to the clues Alan chose to leave unexplained.
Where it was filmed
Filming: Crete hosts Susan and Andreas’s hotel. Dublin locations supply the English settings.
Finale clues to revisit (full spoilers)
Clues to watch for
- Conway’s dedication: a name can refer to more than a person.
- The birthplace assumptions built into James’s recollection of a joke about Melbourne.
- Cecily’s astrology, Aiden’s birthday and the symbol visible in a photograph.
- Why the American visitor wanted Pünd to investigate Melissa’s death.
- The remaining difference between solving a puzzle and taking responsibility for the people affected by it.
Full recap (spoilers)
A remembered meal with Alan finds Susan challenging unexplained details in his manuscript, including the comic Eric reads and a Wizard of Oz photograph. Alan treats her objections as evidence that she has missed his clues. The exchange returns the audience to the uneasy relationship between his skill as a puzzle maker and his indifference to an editor who wants his story to make sense.
Pünd explains that he did not physically kill John. Madeline did, and he feels responsible for bringing her there. An obsessive admirer of Melissa, she hired an actor to pose as the American agent who commissioned the investigation. Her fainting spell concealed an attempt to hide a fan letter in her handwriting. When John confessed, she took revenge during the distraction at the window. Eric had been outside listening, frightened that the police were discussing his own behaviour. Madeline is arrested.
Susan and Andreas visit Stefan. He describes pressure from Lisa and the circumstances of his confession. He recalls being overwhelmed by a small amount of wine on the night of the murder, raising the possibility that he was drugged. Susan is struck by his hesitancy about the meeting in the woods. Later, the name of the Plough and Stars prompts a new way to interpret Leo. Before the final gathering, she confronts Martin: his intimidating behaviour was designed to make Joanne believe he was capable of murder.
At Branlow Hall, Susan identifies Aiden as the former escort called Leo. His birthday, tattoo and the book’s dedication fit together. The apparent Australian connection depended on misunderstanding Alan’s joke: Melbourne can mean the town in Derbyshire. Frank recognised Aiden when he checked in and used that knowledge to demand sex before the wedding. His talk of The Marriage of Figaro and the supposedly broken key were part of that coercion.
Aiden instead arranged to kill Frank and frame Stefan. He drugged Stefan, used his clothing and toolbox, and hurt Chase with the brooch so that Derek would come upstairs and see the false trail. He then murdered Frank and planted money and blood in Stefan’s room, using the missing fountain pen. Susan also identifies Cecily, rather than Lisa, as Stefan’s partner in the woods; Roxana is Stefan’s daughter.
Cecily recognised Leo’s meaning when she read Conway’s dedication. Aiden discovered that she knew and killed her. The police take him away. Susan and Andreas can return to Crete, with freelance editing offering her a way to keep the work she loves. One last visual joke remains for the viewer: Madeline Cain and Aiden MacNeil contain the same letters, a final connection between the two murderers that survives Susan’s decision to put the case behind her.
Where to watch
UK: check BBC iPlayer for Moonflower Murders.
US: PBS lists Moonflower Murders, with Passport access indicated. Check the service’s terms for your location.
PBS listing checked 19 October 2026.
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