I'm not here to debate whether aliens are real (maybe!) or whether they visited our distant ancestors (who can say?). What I can say is that Erich von Däniken can't write a convincing argument to save his life. He'll start by taking his conclusion for granted (I wish I had a count of how many times he says "let us assume") and then state a bunch of things that would be interesting if his assumption were true, never once connecting the ideas in a meaningful way. By the end, he's throwing out things like The Tunguska Event and Edgar Cayce and the atmosphere of Venus, and he doesn't even try to state how these things are related to his central premise, let alone each other. All of the arguments he actually DOES make boil down to one fundamental assumption: the peoples of the distant past could not have had much imagination or sophisticated learning without the help of visitors from another planet. He never explains why they could not. Bad arguments and worse premises. I will admit, this was an engaging listen, but I expect that is more due to William DuFris being an exceptional audiobook narrator.