Skulduggery and Valkyrie are back in the tenth instalment in the bestselling Skulduggery Pleasant series - an incredible and unexpected treat for the legions of fans around the world.

We can't say much but we can say this: Skulduggery and Valkyrie are going to team up with beloved characters from the first 9 books as well as an all-new cast, including new teen co-star Omen Darkly, for an adventure that takes the story to truly global proportions... while answering questions that go right back to the beginning.

And Derek says this: I was halfway through Last Stand of Dead Men, I think, when I realised that I had more stories to tell. I told myself that if Skulduggery and Valkyrie survived the series, I would leave the option open of returning to their world. There were still secrets I need to reveal, after all, and there were still horrors they had to face. They survived the first series. But they're really going to wish they hadn't.