"For the first fifty pages you'll swear that Harrison has been rummaging in an old trunk. Here's that tired old theme...the lost community of Aztecs who have been cut off in a hidden valley by a landslide centuries ago. Presently they will discover the outside world--our world. The stalwart Aztec maverick may even fall in love with a beautiful white explorer...Of course, any reader of Analog Magazine should know Harry Harrison better than that. There…