It’s a tricky one, magic. Who doesn’t love a slice of the impossible in a story, from Mrs Pepperpot’s shrinkage to the BFG blowing dreams or the whole of Harry Potter? But it’s hard to get it right. We all know stories where the magic seems too random (an example for me is Alice in Wonderland) or too convenient, galloping out of nowhere to rescue the plot (e.g. a recent book I read that’ll stay nameless because I don’t want to point the magic finger).

One of the tricky things about magic is that, while every magical story needs its own strict rules – imagine if Tom’s Midnight Garden appeared at lunchtime – some of the best ones break those rules. In The Lion the Witch and the Wardrobe, the Deep Magic from the Dawn of Time (traitors must be sacrificed to the White Witch) is trumped by the Deeper Magic from Before the Dawn of Time (substitution by a volunteer reverses the death). That may sound like a magical cop-out but, when the mice nibbled Aslan’s ropes and the lion roared back to life, I could have kissed CS Lewis. That’s all thanks to his brilliant storytelling. By that stage in the book, Aslan could have tap-danced on a tomato I loved him so much.

So the key lies in the storytelling: the ability to scoop up the audience, whirl them around and fly them to crazy worlds that still convince. Never mind potions and spells, shape-shifters and superpowers: there’s the real magic.