The book presents the letters by Evan Hansen, a non-academic scholar with inquisitive mind. The author was in contact with him, albeit only a few years, due to his tragic death. In second place, it is dedicated to the memory of other, now passed away, American scholars, who investigated the many open questions in the catastrophic past within human memory. Evan Hansen lived in Beryl, Escalante desert, Utah, US. The contacts with E. Spedicato began in 1992 via the first of his letters in this book. The two met one year late: Spedicato, as he loves to remind in the Introduction, "stayed with him three days, sleeping in the best little room of his mobile home, first time for me in such an accommodation... there was toilet, kitchen and many books... He showed me three quarries where well visible were layers rich of partially burned vegetation and of special substances as platinum and iridium". The letters are a great testimonial to an independent researcher, and to the mystery, never solved, of the big catastrophes that affected human history, whose memory could be found in mythology, religion and folkloristic traditions.