Mad Dogs and Englishmen — Paul Magrs

In the 1970s, a retired Oxford professor wrote a fantasy opus about a world ruled by super-intelligent dogs with hands. After his mysterious disappearance, his wife published the story, sparking a huge industry of sequels and films. The Doctor knew the professor when he first started writing the tale, and knows the story is similar to a real and troubled world. Someone is trafficking contraband otherworldly history, and the Doctor must find out who.