He traces his investigation back twenty-five years, when he was searching for an explanation that could account for the evidence he was seeing. The trail led him to Ignatius Donnelly, a congressman from Minnesota who published two books on Atlantis in the early eighteen eighties. Donnelly proposed something radical for his time: that Atlantis was destroyed by a cometary impact. That hypothesis appeared in print in eighteen eighty-three, more than a century before the Younger Dryas impact hypothesis gained traction in peer-reviewed literature. The question becomes whether Donnelly was simply speculating or whether he was reading patterns in mythology, geology, and historical accounts that pointed toward a cosmic catastrophe. For someone studying catastrophism in the nineteen nineties, Donnelly's work offered a framework, a way of thinking about how ancient civilizations might have been swept away not by gradual decline but by sudden, violent events from above.