(upbeat jaunty music) - Originally, there was only going to be one book, "Magpie Murders," but when we started to think about a TV production, the producer, Jill Green, asked me for a second book as a sort of backup, so I thought up "Moonflower Murders."

Lesley Manville said she liked the character of Susan Ryeland so much, could we go again?

- We didn't know that there was going to be more than one series.

- Yeah, it's been lovely to come back and do the final book in this trilogy.

And we like working together, don't we?

- Yeah.

- We were going to publish a new Atticus Pünd detective story.

- She's working on a new book by a young new writer who is the grandson of a famous writer called Miriam Crace.

- The thing that's hanging over the whole family is this childhood that they had.

- Eliot still thinks your grandmother was a monster.

- She was.

- She died in kind of mysterious circumstances.

(Miriam groaning) - Well, I think it's an incredibly intricate story.

- And there's always a twist.

- It takes them to places that they do not want to go.

(jaunty music) - The Pünd-Susan relationship is delightful.

- Every time Susan gets stuck, he appears.

- The two worlds collide, the contemporary world and the 1955 world.

- [Inspector] Excuse me, Mr.

Pünd.

- We have a brilliant sort of meta-theatrical moment.

- We have Eliot writing his book, and you have the other story, which is the way that he views people around him.

- Most of our characters, they're playing two roles, so between us, we've looked at how best to cast it.

- I treat them as two different jobs in a way.

- Well, it is two different jobs.

- The Miss Marples and the Colombos of yesteryear.

The narrative and how the characters merge makes for very good telly.

- I hope audiences will know where they are, but that they are experiencing something new.

- We've managed to keep it going and people want to carry on watching it.

That's what I'm proud of.

(upbeat jaunty music continues)