1. The name of the Furnace Penitentiary actually comes from a horror book for adults that I wrote when I was 18. Back then it was a prison for the criminally insane where the inmates were being hunted by bloodthirsty angels! The book was never published, and I loved the name Furnace so I stole it!

2. In the original draft of the novel, Alex Sawyer's name was Alex Smith, the same as mine! I wanted the book to feel as real as possible, so I wrote it with my name and even suggested that the author biography went something along the lines of: "Alexander Smith was convicted of a murder he didn't commit and sentenced to life without parole in Furnace Penitentiary. This is his story." The UK publishers didn't like the idea, though, so his surname was changed to Sawyer!

3. Likewise, Zee's name was originally Zed. However, there were too many instances of "Zed Said" and it was starting to sound like a Dr Seuss book, so I changed it to the American pronunciation, Zee!

4. Originally I wanted Furnace to be a modern prison, built above ground. Then, for research, I went to investigate some medieval dungeons in Norwich, where I live. My cheeky little brother locked me in a cell deep underground in the old prison, and as I was panicking in the tiny, pitch black (and probably haunted) space I decided that the prison would be far more terrifying if it was buried beneath the earth.


5. The only characters I had trouble describing when I was writing Lockdown were the Wheezers. I knew what I wanted them to be but I couldn't pin them down on the page. So I made a real-life Wheezer head out of rubber, burning and painting it until it looked right. I bought an old gas mask and stitched it on, then gave it a filthy rain slicker. Once I had done this I knew exactly what these nightmare creatures looked like, and what it was like to have one in your house! I even took it round to Jamie's house and left it outside his room one night to get revenge for him locking me in a cell!

6. In the UK the series is called Furnace, but it was changed in the US to Escape From Furnace. One of the reasons for this is that Wes, my editor at Farrar, Straus and Giroux, pointed out that in the States most people have a furnace in their basement, and that they aren't particularly scary! In the UK hardly anybody has a furnace!

7. As part of researching the book I thought I owed it to myself to find out what it was like to shoot a gun. After all, there are plenty of gunfights in Lockdown and I wanted the story to feel as genuine and realistic as possible. A friend of mine, Adam, invited me to come shooting for rabbits with him one weekend. I told him I didn't want to shoot anything living, so he informed me that the best thing to shoot was actually... a cowpat! We spent the morning out on the fields doing exactly that. When you shoot a cowpat with a shotgun it literally explodes – it's like watching a poo volcano! There was one unfortunate incident when we both shot a giant cowpat at the same time. It rose up, caught the wind, and surged in the direction of Adam's little brother, who was out shooting with us. The poor boy turned around to see a wall of cow dung flying towards him. He didn't have time to dodge. He didn't even have time to close his mouth. It was so disgusting! As well as being hilarious, the experience really helped me describe what it was like to fire a gun.

8. When I first pitched the series to my agent I misspelled the name of the book in the email, calling it FUNRACE (I was so excited about the idea I sent it off without checking)! She probably thought the story was about a jolly marathon – until she read the synopsis!

9. I called one of the villains in the book Kevin Arnold without noticing that it was the same name as the kid in The Wonder Years (even though I always used to watch the show). I could have changed it, but thought it would be interesting to have such a horrible character share the name of one of the nicest kids on television!

10. In the trailer for Furnace (which you can see here), the boy burgling the house is my little brother, Jamie, and the Wheezer is actually me!