For a decade, the world's best-funded scientists searched the globe for the impact crater behind the extinction of the non-avian dinosaurs, unaware that two geophysicists working for the Mexican oil company Pemex had already mapped it. This episode reconstructs the near miss: Walter and Luis Alvarez's 1980 discovery of an iridium spike at the K-Pg boundary in Gubbio, Italy, the paleontological community's resistance rooted in uniformitarianism and the three-meter problem, and Glen Penfield and Antonio Camargo's 180-kilometer non-magnetic bullseye under the Yucatan that their bosses dismissed as a volcanic caldera.

We follow the 1981 conference collision, the drill cores thought lost in a warehouse fire, and the 1990 matchmaking by a Houston Chronicle journalist that connected Penfield with graduate student Alan Hildebrand and led to shocked ...