A lot of the stories I loved most as a child involved doors. Aged about 4, I suppose, I passed through the small, latched door in the hillside, into Mrs Tiggywinkle’s flagged kitchen, filled with the ‘nice, hot, singey smell’ of ironing, busy and reassuring. A few years later came the doors into Narnia, the Secret Garden and Wonderland, Bilbo Baggins’s ‘perfectly round’ green door with its shiny yellow brass knob ‘in the exact middle’, the door into the Yellow Dwarf ’s home in the orange tree, and the dark door into Bluebeard’s bloody chamber . . . But reading to my own children, the door I’ve been happiest to pass through again is the door into Tom’s Midnight Garden – a door one can only imagine because, unlike most of the others, it is never described.