Esther doubts the "foreign" origin of the plague bacteria. Covered-up evidence points to a scandal: Was there an accident with a vaccine? With her research, the courageous biologist puts herself in danger and in the crosshairs of the Prime Minister's movement. Meanwhile, Charlie mourns the loss of his wife, who is officially listed as "Patient Zero". He narrowly escapes a deportation squad and makes his way to Esther. Charlie goes into hiding with her family to find out the truth together.