Worlds Apart — Richard Cowper

George Cringe is a middle-aged school-teacher, married with several children. His marriage, while not a failure, is hardly a great success, and he is somewhat drawn towards a fellow teacher, Jennifer Lawton, who is much younger than he is. For relaxation, George has taken to creating an endless SF saga set on the planet Agenor, where his hero and heroine, Zil Bryn and Orgypp, face various problems, their current one involving an outbreak of psychedelic mushrooms.
Meanwhile, on the other side of the galaxy, on the planet Chnas, life Zil Bryn and his wife Orgypp. Bryn is currently composing a long weird narrative called Shorge Gringe's Pilgrimage, set on a strange world called Urth . . .