2021/019: The Left-Handed Booksellers of London -- Garth Nix

2021/019: The Left-Handed Booksellers of London -- Garth Nix

“Children’s writers,” said Merlin. “Dangerous bunch. They cause us a lot of trouble.”
“How?” asked Susan.
“They don’t do it on purpose,” said Merlin. He opened the door. “But quite often they discover the key to raise some ancient myth, or release something that should have stayed imprisoned, and they share that knowledge via their writing. Stories aren’t always merely stories, you know." [p. 76]

Susan Arkshaw's mother has always been rather vague about Susan's father: so Susan, who's won a place at the Slade to study art, decides to head up to London a few months before her course starts, in the hope of discovering the other half of her heritage.

It's 1983, but not quite as we know it( no spoilers )