In Terry Pratchett’s 14th Discworld novel, it’s Midsummer Night – no time for dreaming.‘When you start believing in Spirits, you start believing in demons, and then before you know where you are, you’re believing in Gods. And then you’re in trouble.’Reality is all very well in small doses. It’s a perfectly conventional and convenient way of neutralising the imagination. But sometimes when there’s more than one reality at play, imagination just won’t be neutralised, and the walls between realities come tumbling down. Unfortunately there’s usually a damned good reason for there being walls between them in the first place. To keep things out. Things who want to make mischief and play havoc with the natural order…