This book gives a fascinating account of the development of fact-finding and formulation of hypotheses concerning the Tunguska phenomenon. This is a subject, which has had my attention for many years, but this book is by far the best treatise on the subject which I have come across. The author does an excellent job in explaining the complicated subject matter in an easily understandable way. Moreover, a gallery of interesting personalities is presented, starting with Leonid Kulik who initiated the scientific expeditions in the 1920s. An intellectual adventure - highly recommended.