I love problem-solving. In Enigma I wanted to hide the solution to the mystery that is set up in the story in such a way that a reader could find the answer but then cover it up again so that another reader would not have their fun spoiled. This meant I needed to invent some kind of ‘relockable safe’ – but it had to be made of cardboard, and it had to be affordable, and it had to be robust, and it had to be reliable! It took AGES to come up with the concept and ages more to refine it to the point where I knew it would work every time but eventually I hit on a workable design. In the back of every copy of Enigma there is a ‘magic box’ with spinning dials and a sliding panel that can be unlocked to reveal the solution to the mystery code and relocked so that the next reader can have the fun of doing it themselves. And it all fits into the back cover of the hardback book. (You can tell I am just a little bit proud of this!)
The inspiration for the story was the special relationship between my oldest son, James, and his grandpa.