Kazantsev also showed great interest in the mysteries of science and interpreted them in his own way. He published a number of articles, essays and works of fiction dedicated to the mystery of the Tunguska meteorite (“Explosion”, “Guest from Space”, “Tunguska Catastrophe: 60 Years of Speculation and Controversy”). In them, he expressed the version that the meteorite was actually an alien ship that exploded upon landing.  In addition, Kazantsev was interested in the hypothesis of paleocontacts, collected information about legends and archaeological finds that could confirm this hypothesis, and wrote articles and essays. Kazantsev can be called one of the pioneers of Soviet ufology.   Kazantsev's return to active literary work took place in the early 1970s. During this period, he wrote the novels “Stronger than Time”, “Faetes”, “Dome of Hope”, which were still strictly adhered to from an ideological point of view. At this time, several collected works of Kazantsev were published, and he himself became one of the active “engines” of the so-called “Young Guards” school of fiction. In the 1980s, Alexander Kazantsev published novels about Pierre Fermat, “Sharper than the Sword,” and about Cyrano de Bergerac, “The Bubbling Emptiness,” where he tried to combine his usual fantastic ideas with the surroundings of a “musketeer” historical novel. The works of the following years fit well into the themes he had already mastered - this is the trilogy of communist utopias “The Mystery of Zero”, “Don Quixote of the Universe” and “After a Millennium”; the “Other Worlds” duology and the historical-fantasy duology “The Star of Nostradamus” Contents: 1. Alexander Petrovich Kazantsev: Stronger than time2. Alexander Petrovich Kazantsev: Faetians3. Alexander Kazantsev: The Burning Island (Fantastic novel with illustrations)4. Alexander Petrovich Kazantsev: Against the wind5. Alexander Petrovich Kazantsev: Tragedy in New Mexico6. Alexander Kazantsev: Planet of Storms7. Alexander Petrovich Kazantsev: Sharper than a sword8. Alexander Kazantsev: Bubbling Emptiness (with illustrations)9. Alexander Kazantsev: Kaissa's Gift