The human challenge trial had 36 un vaccinated subjects, all between the ages of 18 and 29. All volunteers agreed to be infected with covid in a concentrated dose administered through the nasal cavity. Part one was about what happened when ansell keys invited a group of young men to spend a year in a dingy set of rooms under the university of minnesota football stadiam. This episode is about the strange way that so many scientists think about the morality of human experiments.