This script has been lightly edited for clarity.

 Jace Lacob: I’m Jace Lacob, and you’re listening to MASTERPIECE Studio.

Just as the night sky is darkest before dawn, our story grows increasingly complex before all of the pieces are sorted. At the end of Episode Five, the world of 1950s Devonshire — and the investigation into the murder of glamorous actress turned hotelier Melissa James — is turned on its head as Detective Pünd makes a most unexpected confession.

CLIP

Chubb: There’s one thing I don’t get, Mr. Pünd. If Dr. Collins killed Melissa James, who in the blazes killed John Spencer?

Pünd: That is the second part of the puzzle, Detective Inspector, and I have a confession to make. The person who killed John Spencer was me.

Back in Susan Ryeland’s world, questions are mounting. Who killed Cecily? What does Frank Parris’ murder have to do with this case? And why is Lisa so set on getting Susan out of the hotel? But by the final episode, Susan’s expert detective work pulls through. She channels Agatha Christie by gathering all the suspects in the room, slowly revealing the identity of the killer as Pünd watches. 

CLIP

Susan: It is clear now that Stefan Leonida did not kill Frank Parris. Cecily knew the truth and it was that which put her own life in danger.

By the end of Episode Six, it appears as though Susan managed to get it all. She solved the case and landed a remote publishing job which she can do from the hotel in Crete alongside Andreas. In a symbolic gesture to the Gods one evening in a cave on a cliff, Andreas and Susan burn all of her notes and documents from this case, finally putting it all behind them. 

CLIP

Susan: I brought something with me. I thought I might need it.

Andreas: What is it?

Susan: It’s everything that James gave me, and all of my notes from Branlow Hall. I don’t need them.

Andreas: Are you sure?

Susan: I’ve never been so sure of anything in all my life.

Andreas: Then let’s make an offering to the Gods, to thank them for bringing us back together. And to release you from the dark shadows, the memories of what we’ve left behind.

Susan: An offering to the Gods.

As the documents go up in smoke, we see one final anagram arranged in the burning letters, a small detail that raises a whole slew of questions. Once again, writer and creator Anthony Horowitz sits down with us to discuss all that went into Moonflower Murders and wrap up this magnificently classic yet modern meta-mystery series.

Jace Lacob: We are joined once again by Moonflower Murders creator, writer and executive producer, Anthony Horowitz.

Anthony Horowitz: Thank you, Jace.

Jace Lacob: To me, the most important part of a murder mystery, you said, is the motivation. In Episode Six of Moonflower, three killers are unmasked, each with their own motivations. Over the course of your career, you’ve covered seemingly every variation of motive. How did you look to challenge yourself within the motives of Moonflower Murders?

Anthony Horowitz: The motives are very, very different in this series. You’ve got the modern motive, which turns out to be really quite foul and sorted and unpleasant and has led to a very modern death, as Aiden is unmasked as a wife killer. Whereas in the past, you’ve got Madeline Cain, whose motive is actually slightly sad. We don’t know very much about her as a human being, whether she is married or single, probably single it would seem, whether she has been happy in her life, but being this sort of absolutely devoted fan of Melissa James, and that all her life has been about knowing every single film, every single prop, every piece of information about her, you get the sense there must be a sort of an emptiness in her life.

And the fact that she then decides to kill, to punish somebody for what they have done, and gets the wrong person is, I think, sort of a tragedy. And I loved her last line, that little last scene with Pünd where she sort of says goodbye,

CLIP

Madeline: I will be giving you my notice, Mr. Pünd. With immediate effect.

Atticus: I accept your resignation.

Anthony Horowitz: I find her a wonderful character and I say that not as a writer but as somebody who so admires Pippa who played the part.

Jace Lacob: Pünd does seem quite saddened by Madeline’s betrayal. Does her betrayal make Pünd a bit more human, a bit more fallible? After all, he blames himself for what happened to John Spencer as he brought her there. And at the end of Episode Five says as much that it’s his fault.

Anthony Horowitz: Well, I mean, he does actually commit a small crime himself because he is aware from the very start, if you go back to Episode Two, when the American agent turns up at his office to give him the job, he knows something is wrong because he makes a couple of allusions to the fact that Schultz couldn’t possibly have flown from New York to London in the amount of time. He must have already been there. So, I think he’s doing the investigation in part to work out this inner puzzle for himself, which does lead to further tragedy. And yet, when at the end of Episode Five, he says, I know who killed the husband, it was me, I think he does mean that. He blames himself.

Jace Lacob: There are numerous clues leading to Leo sprinkled throughout Atticus Pünd Takes the Case, Algernon’s number plate, the Red Lion pub, Richard the Lionheart, Eric’s comic, Bert Lahr, etc. How do you track all of these while writing something like this? Do you retrofit them? And does it force you to sort of backfill in a way? Or are you kind of filling in as you go along? I’m fascinated.

Anthony Horowitz: I’ve got to ask you a question, if I may Jace. Did you spot them?

Jace Lacob: The number plate, absolutely. Bert Lahr, yes, which I thought was very strange.

Anthony Horowitz: Did you get their significance? Did you realize there was something going on?

Jace Lacob: No, no, no. Only later, only later.

Anthony Horowitz: Again, I was talking to you about trying to do things differently. When we first spoke, I said that the whole idea this time was to try and come up with new ideas. And I loved the idea that there would be visual clues that nobody would notice, just sprinkled throughout. There are many, many more, incidentally, than the ones that are shown in the flashback. If you ever watch the series a second time, you will see that there are lions everywhere.

And that just made me smile. I just love the idea that you can have a series of clues, almost like arrows pointing to where you should be looking. When you see that number plate, L10N5, which in fact makes “Lions”, you’re not looking up a number plate, no one is actually talking about that. They’re talking about the fact that the car has been involved in an accident. So, you may notice that it spells out the word, but I think it’ll just slide, hopefully, over your subconscious, and you won’t realize what I’m doing.

In terms of how I did it, having had the idea very early on that that’s what I was going to do, I sort of went and searched for every lion, in both literature and art and the Bible and films and anything that I could think of, names of lions. I think there are many, many more in the book than there are in the TV series, interestingly, as well. And then, as I was writing, I threaded them through, making sure that there weren’t too many clustered in one section of the book, and that they were throughout, rather, and hopefully completely unnoticeable.

Jace Lacob: Alan recognizes Aidan as Leo when he checks in at Branlow Hall, but how does Alan deduce that he’s Frank Parris’ killer? Is it merely because he connects him to Frank? And why doesn’t Alan go to the police?

Anthony Horowitz: I think that Alan recognizes Aiden, obviously, and knows everything about his dark history. And when he sees him again, as it were, in a new guise, pretending to be the happily married husband of the hotel’s owner, or one of the owners, and in charge of PR, and all smiles, and not admitting anything, I think it’s fairly easy for him to suppose that this man is probably the killer of Frank Parris. After all, they both knew Frank Parris too. So that sort of gives him at least half a motive and certainly, and perhaps half of whatever else it is that proves that he would have done it.

So, he doesn’t know for sure. He doesn’t know a hundred percent, but he doesn’t care anyway. You know, Alan Conway is so amoral, so cold blooded, so self-centered, that he doesn’t care who killed this man. It’s just, here’s an idea for my book, and I can have some fun with this guy at the same time. Much more fun to put him in the book than to shop him to the police.

Jace Lacob: What did Cecily see in the Pünd novel? Was it the Madeline Cain/Aidan MacNeil anagram that Susan missed? Or was it just seeing the glyph on Aidan’s shoulder and connecting it finally to the Leo?

Anthony Horowitz: It’s Leo. It’s the fact that the book is dedicated to Leo. That’s what does it. And that her husband is a Leo. And to her, Leo, I think in the book, is actually her nickname for him. But it’s enough that Leo and astrology is at the heart of her life. And also of course, I think certainly in the book, I can’t remember if I put it in a TV series, if you are married to a psychopath who has also been a sex worker who is a sort of a generally dreadful man, you probably are going to get an inkling of it after a time.

So, I think that seeing the book, the dedication to Leo and Frank would have been enough for her to say, hold on a minute, I’m married to Leo, and that of course is her undoing.

Jace Lacob: I do love that it’s in the dedication and not actually in the book. It’s page one when you open the book.

Anthony Horowitz: There was no alternative because if it had been somewhere in the book and not in the external aspect of the book, which is to say the blurb, the back cover, the title, or the dedication, all of which I considered, then the two stories, the story set in Tawleigh and the story in the modern age would have had to be very, very similar for it to work, and I didn’t want to do that.

I wanted to have two completely separate stories, so therefore the clue, the big clue that connected Aidan to Leo to the murderer had to be something that was, as it were, outside the book, even though it’s actually in it, as you correctly say on the first page.

Jace Lacob: There are some key differences between the ending of Moonflower the series and the novel. Why did you opt to change Aiden’s fate, arrested and in prison, rather than jumping in front of a moving train? Is there a sense that television murder needs to be tidier in some way, that justice restored, the guilty punished? Or were you saving him for something else?

Anthony Horowitz: No, it wasn’t that. It wasn’t either of those things. It was simply my feeling that having exposed Aiden as the killer that that was it. There are lots of endings in this series. Once the murderer has been revealed, then Susan has to return to Greece. She has to be given another job. She has to then patch things up with Andreas. They then have to go to the cave together to make their libation to the gods. And in the course of that, the final anagram. And all of the lions have to be revealed, and then the anagram at the very end as a sort of a fun thing for the audience to have as a last image of a show.

And that, as I speak to you, is seven things. Where would I have fitted in the sequence of Aiden taking a swipe at Locke, running out of the house, writing a letter, driving a car to a station, throwing himself under a train? All of that’s in the book. It wouldn’t have fitted in the end. There’d have been too much. When you get to the final second reveal in the show, you don’t want to hang around too long, and as it is, you still have another five minutes before the closing credits.

Jace Lacob: Did the Aiden of Moonflower the television series love Cecily, or did he merely see her as an escape from the drudgery of his life, much in the same way that Susan uses Cecily’s disappearance to escape the drudgery of her own? Or is it more complicated than that, the way he says he tried to love her?

Anthony Horowitz: You know, Jace, you do ask the most wonderful questions. You should do this for a living. It’s a great question. And I can only partly answer it. In the book, it’s much, much more cold blooded. He married Cecily for her money, for the hotel. He would have probably murdered everybody, her sister, her parents, every single member of the family would have died. He had no love for her at all and was a psychopath. But that doesn’t work in television. I think as I may have said to you earlier, one has to have a modicum of sympathy for the killer. You have to slightly empathize with them.

And so, I think he is a much softer villain in the TV version of it. And certainly the actor, Will, who is so good in the part, does bring, I think, especially during that sort of… those scenes where you all surround each other in the library and the detective says, it wasn’t you, it wasn’t you, it wasn’t you, it was you, can be a little bit, sort of, formulaic, a little bit matter of fact. But I think Aiden does have a real sadness about him, a sense of loss. And I think he did love Cecily, actually. I do think there was a love between them. And I think he probably murdered her in desperation of everything that he was going to lose, life with her, Roxana, the hotel, comfort, a position.

You know, he had found himself a good life and killed to keep it for himself. And I understand why he did that, and as I say, that is one of my first rules of writing, which is that the killer can’t just be a psychopath, the killer has to be somebody one understands.

MIDROLL

Jace Lacob: You mentioned Susan channeling Agatha Christie in the final episode, and she does create this sort of Poirot style tableau, gathering all the suspects in the room and then slowly revealing the identity of the killer, as Pünd watches her. How important was it that she steps somewhat fully into the role of Golden Age style sleuth here?

Anthony Horowitz: I enjoyed it because she knows it’s ridiculous in a strange sort of way, and she’s nervous about doing it. She has to sort of, you know, give me a minute, to Andreas, as they come down the stairs. I was going to get myself ready. And then Pünd there to take her hand and to stand beside her and to just offer her a few nudges. It also incidentally is a mirror reflection of what happened in the first season where Pünd had the wrap in a room with everybody there in a public house, a bar, and Susan was standing to one side and she’d gone back in time to watch him. Now he goes forward in time to watch and to help her.

So, there is an enormous satisfaction. I try to avoid formula and cliche and stuff that you’ve seen before, but there are some scenes that provide enormous satisfaction, particularly if they’re handled with a certain amount of warmth and humanity, and the wrap is definitely one of them.

Jace Lacob: I love when he tells Susan,

CLIP

Susan: It’s hopeless. I’ve asked a thousand questions, and I still don’t have any answers.

Atticus: Oh, but you have many, many answers. That’s how it works for the detective.

Susan: Um, I’m not a detective.

Atticus: You have so much that is in your head; truth, lies, half lies, misdirection. But suddenly you see something which may seem to have no relevance, but it untangles everything, and at once you have total clarity.

Jace Lacob: And it’s such a, to me, a brilliant encapsulation of the essence of the detective, but also the editor. Is this the lightbulb moment where she realizes who and what she is?

Anthony Horowitz: I think Susan does not want to be a detective. I think that really, she goes back to Crete at the end of this series and goes to the cave of Zeus and tears up all the books and the notes and everything else. I didn’t have her burning books for obvious reasons, Pünd would not have approved. But she does get rid of all the notes and the thinking that’s gone into it, because she does want an ordinary life. I don’t think anybody in their right minds really wants to spend time with killers and with death.

And Susan has other dreams. She’s much more interested in books and fiction than she is in death and unpleasantness. So, I don’t think she does find herself there, I think it is the opposite. I think she loses herself.

Jace Lacob: She says to him, “I really do think it is goodbye this time.” But he reminds her there’s something she missed. And she won’t quite give up the ghost, as it were. Is that her subconscious refusing to give up Pünd, teasing her with a missed clue? And can she ever really say goodbye to someone who has become her other half?

Anthony Horowitz: Speak to any editor, speak to any editor, and you will know the fanaticism, the dedication they have to wheedle out every single last copy and mistake, last typographical mistake, last bit of fact that is wrong. It is that sense of not leaving alone, that something is unfinished. That’s what drives her to do more. She wants perfection. I think that’s what editors are like. It is the editor in her, not the detective that is doing that in the last chapters of the book and the last minutes of the series. She’s not asking questions; she is reading text. That’s what editors do.

Jace Lacob: So, we talked about this, Andreas takes Susan to the cave in a beautiful sequence, and she burns her notes, making an offering to the gods to free her from the dark shadow of Alan Conway, only to miss Alan’s final clue, the Madeline Cain anagram. What’s embedded in this scene? Is it an exorcism for Susan, a sort of burnt offering that cleanses?

Anthony Horowitz: Definitely that, but it’s also an offering by me, the author, to my audience to say, let’s have one last joke, almost at Susan’s expense. We’re going to know, I know, and you’re going to know, but she is not going to find it. Now that’s different from in the book. In the book, she finds the anagram for herself. But I just loved the idea. Citizen Kane is the inspiration, obviously. The last shot of Citizen Kane explains the entire film with just a name written on something. But you see, I won’t do a spoiler here in case anybody hasn’t seen this marvelous masterpiece of a movie. But that’s what it was. It’s an expiation to me. To me, it’s somehow very apt that the show finishes with a page of the book going up in flames.

Jace Lacob: So, you’re Rosebud. Amazing.

Anthony Horowitz: It’s my Rosebud, yes.

Jace Lacob: Mm. “Books are like doors,” you once said. “They have the same proportions as a door, the same mechanism as a door, in the sense that they open, and you can travel through that door into other worlds.” You relish in puzzles, anagrams, riddles. I don’t know if you still do in your home, but at one point you had a secret door concealed behind a bookcase that led to a hidden room.

Anthony Horowitz: I have a new home. I have a new home and another secret door.

Jace Lacob: New home. Another secret door. What draws you to mystery, to the hidden, the unknown, toward opening those doors?

Anthony Horowitz: To be honest with you, Jace, it started with being unhappy. Unhappy as a child, unhappy with myself, unhappy as a teenager, and always believing that my life and everything I saw around me was a facade. That actually if I looked hard enough, I would find the secrets behind everything that was around me.

So, a little tiny example is that there was a furniture shop near my house where I lived in North London. And I used to walk past it. Like, for two years I walked past it, and not a single stick of furniture was ever sold. It was always the same. So, I knew, I didn’t think, I knew that it wasn’t really a furniture shop, it was some kind of, you know, it was a front, it was a secret.

As a child being shown around museums, or old stately homes, I was bored, I didn’t have the imagination then to understand that history can be exciting and marvelous. So, I’d be looking, I’d be tapping the walls for the panel that would open, the wooden panel that would swing open with a staircase taking me to somewhere else that wasn’t this boring place.

And that is how I’ve always been throughout my life. My love of Tintin, you know, Hergé’s Adventures of Tintin, it’s the secret passages I love, all of the secret passages in those books. And I guess that in my work, in my writing, and in my imagination, and in my life, I’ve always been searching for secret doors to take me to better places. And it just won’t go away.

Jace Lacob: Anthony Horowitz, thank you so very much.

Anthony Horowitz: It was a wonderful interview. Thank you.

And with that, we say goodbye to our dear detectives Susan Ryleland and Atticus Pünd… for now.

Next week, we travel to the quaint town of Marlow, where three everyday citizens take it upon themselves to investigate a local murder. 

CLIP

DS Tanika Malik: Mrs. Potts, I can’t have you interfering. This is a police matter now.

Mrs. Potts: Of course. And I’m sure you’ll do an excellent job.

But before we move to our next exciting mystery, The Marlow Murder Club premiering next Sunday at 9pm Eastern, we’re not quite ready to say goodbye to Moonflower Murders. Catch a special bonus episode with a cast member who speaks about their homicidal role in Moonflower Murders. That’s next Thursday, October 20th on MASTERPIECE Studio.