The Plague Doctor goes where sickness has already entered. They were doing it before the Covenant. Walking into sealed rooms. Studying what spread. Looking for the pattern beneath the fear while everyone else tried to escape. The Covenant made them sharper. Better at seeing what moves through blood, breath, rot, and touch. Better at finding the source. Worse at looking away. The mask was never really for them. Not after the change. The Plague Doctor understands the line between medicine and infection better than anyone. They also know how easy it is to cross.