In a secure air-locked chamber in the world’s largest research hospital, Dan Chertow and a half-dozen other scientists in astronaut-inspired protective gear are carrying out a microscopic search inside Covid-19 victims to try to unlock one of the pandemic’s biggest and most disturbing mysteries.

On this episode, Bloomberg’s Jason Gale joins the critical-care physician on his exhaustive hunt for the coronavirus in the body and brain of fatal cases. By looking for clues in the deceased, Chertow aims to understand how to treat and prevent the disease in the living, including the lingering symptoms wracking millions of Covid “long haulers.”