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 quartz in samples sitting in a New Orleans storage facility. From there we break down the physics of the impact itself: a roughly 10-kilometer carbonaceous asteroid arriving at 20 kilometers per second on a spring day, as revealed by fish bones at the Tanis site, striking a shallow sulfur-rich carbonate platform, generating tsunamis, a global thermal pulse that ignited forests, years of darkness, acid rain, and then a greenhouse whiplash. We close with the peak ring drilled by Expedition 364, acoustic fluidization, the isotopic evidence that ruled out a comet, the cenote ring that sustained the Maya, and the hydrothermal system that may echo how life first began.

• Why iridium levels up to 160 times background pointed to an extraterrestrial source and why paleontologists still resisted
• How aeromagnetic and gravity data revealed a 180-kilometer subterranean ring that corporate secrecy kept hidden
• The seasonal fish-bone evidence from Tanis and why hitting a gypsum-rich shallow sea made the impact far more lethal
• Fossilized 16-meter tsunami ripples under Louisiana and a 10-centimeter death layer in New Jersey
• Ruthenium and chromium-54 isotopes that identify the impactor as a carbonaceous chondrite from beyond Jupiter