Its one of those stories you read about and wonder why it hasnt been made into a movie. A down on his luck writer finds this schizophrenic guy who wrote this absolutely bizarre piece on his journey to an underground civilization. So the writer takes it, spruces it up, and publishes a really popular science fiction story. You could make it about the ethics of this writer using the paranoid delusions of this poor man to create award winning books. Like Rainman but for science fiction.