Imagine a magical doorway.
Does the door have a dial above it with four differently colored options each representing an exterior location, as in Howl’s Moving Castle by Diana Wynne Jones?
Is it a wrought iron gate appearing unexpectedly in an (also unexpected) iron fence surrounding mysterious circus tents, as in the beginning of The Night Circus by Erin Morgenstern?
Or is it a large old wardrobe filled with winter coats—except that when you step in and try to find one your size, the back is further away than you’d expected and you keep pushing through coats until they become soft green branches dusted with snow as you step into Narnia, as in The Lion, the Witch and the Wardrobe by C. S. Lewis?
Perhaps the door is low and round, hidden by ferns on the slope of a hill, and the magical part about it is who lives behind that door, as in The Hobbit by J. R. R. Tolkein.
It might even be something natural and commonplace like a rabbit hole, except that if you fall into it, who knows what might happen next … as Alice learns in the classic children’s book by Lewis Carroll.
Or what if the door is only there if you cut it out using the subtle knife from Philip Pullman’s Dark Materials trilogy?
And numerous sic-fi authors and script-writers have explored variants on wormholes connecting you to far-flung planets or times.
But no, this passage is of your own unique devising, and it’s even more mysterious and strange than any you’ve read about before…
In Silent Lee and the Adventure of the Side Door Key, I wrote about a side door in an old brick house on Newbury Street in Boston. The key might be long lost and the door out of service—or perhaps the key is kept carefully out of sight on a string around the neck of an almost-fifteen-year-old girl named Silent who attends a magical academy on the other side of that door…
Doors can be magical, albeit not that often. We go through doors all the time but they rarely open onto another world. When they do, are there rules to it? Rules help create the structure and challenge of good narrative tension. If it’s too free-form and easy to pop anywhere anytime, what’s to challenge the protagonist and create tension for the reader?
Kell, the magician in V. E. Schwab’s A Darker Shade of Magic, must carry an artifact from the destination world, and the door has to be in the same place in both worlds (tricky unless you find a building that stands in both—he favors an old tavern that is common to multiple versions of London).
Now it’s your turn. Introduce a doorway that unexpectedly leads to another world. Use a paragraph or several to set the scene and have a character (first person or third) discover a way through the very fabric of their world’s boundaries.
Now what? The door creaks open and you step into… Where?
Write another paragraph or two as you step through that doorway with your protagonist. Maybe start with hints of something mysterious and magical beyond, then expand their knowledge of the new place with more clues.
You might start simply with a scent they don’t expect (such as a hint of caramel in the cold autumn breeze in The Night Circus).
Or very different weather. Lucy steps out into fresh snow as she enters Narina in The Lion, The Witch and the Wardrobe.
And then your protagonist meets someone from this new world.
Lucy promptly encounters a faun with packages under one arm and an umbrella in the other.
Neil Gaiman folds the door into the mysterious character you meet in his Neverwhere. Another world opens only when protagonist Richard Mayhew stops to help a young woman who is from a very different London. Fittingly, her name is Door.
What character will your protagonist meet? Craft that encounter now.
You’ve just begun a wonderful story. Let it incubate until you know what is going to happen next.