This is a frightening story to wake up to, and there aren’t a lot of reassuring answers right now. The U.S. State Department and the CDC say they are both closely monitoring a situation in Siberia, after the suspicious death of a 28-year-old Russian lab researcher who was studying the pneumonic plague. She officially died of pneumonia of an “unknown” origin, but testing is underway with 200 of her colleagues under medical observations with at least 5 facilities under quarantine. The pneumonic plague is a rare and deadly lung infection that is passed from human to human and is considered the most dangerous form of the disease.