The story is purportedly relayed back to earth via the Gridley Wave, a sort of super radio frequency previously introduced in Tanar of Pellucidar, the third of Burrough's Pellucidar novels, which thus provides a link between the two series. The story-teller is Ulysses Paxton, protagonist of the previous novel, The Master Mind of Mars, but this story is not about him, rather, it is the tale of Tan ...