(I particularly like Pooh Bear’s wedding: how he’s found a great girl and his mother is overjoyed; but most of all, I love that Stretch is his best man and Jack—the world-famous Jack West—is the second-best man! Stretch and Pooh’s friendship is one of my favourite things in this whole series and it has lasted since they both dived from cover at the same time in Seven Ancient Wonders to rescue Lily. That friendship is really emblematic of the whole series.)

Because really, when I think about it, this series is about friends and family and love, and how your friends lift you up and help you reach further than you could reach by yourself. In the climax, for instance, Jack, with the help of those who love him—Lily, Zoe and Alby—literally reaches further than he could have by himself.

And over the course of seven novels, that’s been a consistent theme. Having Lachlan Adamson carry his brother, Julius, to safety in The Five Greatest Warriors, and when he’s asked if he needs assistance because Julius must be heavy, he says, ‘He’s not heavy, he’s my brother.’ (This also made their deaths in The Three Secret Cities, especially Julius’s when he confronts the Knights of the Golden Eight, more tragic.)

I should also add that I enjoyed writing about Jack’s fame. He has always acted in obscurity, out of the world’s eye, and I felt that after all he did, over twenty years, he deserved recognition! That said, I was always intrigued by how Neil Armstrong handled his massive global fame—with quiet dignity. So I modelled Jack’s reaction to his fame on Armstrong’s.

Ultimately, this book is an ending. It’s a send-off for a bunch of characters we have known for sixteen years and a chance for readers to say goodbye to them. It’s very rare to end a series. Indeed, it’s not something I’ve ever done before, so it’s all rather new to me, too.

But I’m happy to do it here.

I wrote ‘THE END’ and I felt very content.

We start this book seconds after The Two Lost Mountains, which ended with Jack West’s ingenious Russian Doll plan. You don’t waste time getting right into the action for this last book!

Essentially, The Two Lost Mountains and The One Impossible Labyrinth are one story. They were designed to flow right into each other. (Truth be told, the last four books of this series are essentially one single story: once I decided to write The Four Legendary Kingdoms I actually planned out the last three books in the series. Indeed, you can see many things mentioned in 4LK coming to life in the later books: things like the two sacred trees and the Lifestone were mentioned way back in 4LK.)

And, hey, I like a book to start quickly! Always have.