Burroughs is one of the 20th Century’s finest storytellers because he had the good fortune to JUST HAPPEN to hear stories of various heroic characters. Heck, his uncle was John Carter, who was the fist human to get mysteriously teleported to Mars. (Something that happened to at least one other guy some years later.) So he was able to get the first-hand scoop of Carter’s adventures on the Red Planet.
Anyway, the novel ends when David (now Emperor of a coalition of tribes) returns to the surface for books and tools needed to bring real civilization to the humans. He pops up in the