Has anybody read these and know anything about the spin offs from it? Apparently its a series of 8 books by Nicholas Sansbury Smith, however, I came across a couple of books the other day called Lost Valley and Satans Gate by Walt Browning that are apparently fan fiction spin offs that first got published through Amazon Kindle and have now been properly published in paper, e book, audio etc.. I was wondering if there were any more spin off books or series from this that people know about as it sounds as though there is, but i cant find anything about it. Just seen there is a prequel book. For those who have read the series, is it worth starting with the prequel or just go to book 1?