One of the most mysterious submarine disasters in history was the sinking of the HL Hunley, a Confederate Civil War submarine. This 40-foot-long tin can was the first to successfully attack another ship—but the results were as disastrous as they were historic. Shortly after its torpedo exploded, the Hunley disappeared off the coast of Charleston. The mystery of what happened to the Hunley and its crewmembers persisted for over a century, until the sub was finally recovered in 2000. But the discovery of the sub only led to a more puzzling mystery—the skeletons of all eight crew members were found in the cramped interior, each seated at their stations with no indication they ever tried to escape.

Those mysterious deaths piqued the interest of today’s guest Rachel Lance, the leading underwater blast trauma specialist in North America, who found the case so fascinating that she banked her PhD career on solving it. Lance, the author of the new book In the Waves, provides a definitive answer to what happened to the submarine and its crew on that fateful night. During three years of investigation, she went through archives, delved into previously unknown aspects of blast and shock science and built her own mini-submarine and explosives.