Prologue - The Tunguska Event

June 30th, 1908, a forty-megaton explosion obliterates a swath of ancient Siberian forest half the size of the state of Rhode Island, yet leaves behind not a trace of the object that caused it. What was it? A meteor? A comet? An alien spacecraft in reactor overload? — Or something stranger still? Learn more about your ad choices. Visit megaphone.fm/adchoices