If ever there was a book which deserved a prequel it’s Mr Penumbra’s 24-Hour Bookstore, and Robin Sloan has kindly obliged with the delightful novella Ajax Penumbra, 1969. There was so much implied backstory in the original novel that it would have been a crime not to have explored it further, so here we get to take a look at a young Mr Penumbra, just starting out on the path that would lead to 1960s San Francisco, a 24-hour bookstore, a sunken ship and two men who would come to shape his life.
