The deadly hantavirus has killed dozens of Native Americans, so when a reputable pharmaceutical company claims to have developed a vaccine against the deadly disease, it should be good news. But when ImmuVac asks Dr Isabel McLain to conduct a clinical trial of the vaccine on the Blackfeet reservation in Browning, Montana, the proposal gets a distinctly mixed response from both her and the suspicious Blackfeet. Is the new drug truly safe, or are the Blackfeet being used as human guinea pigs?