Dr. Nancy Jaax and her lab partner, Dr. Peter Jahrling, must take matters into their own hands to determine the source of the virus before it spreads; Dr. Jaax convinces an employee to hand over samples from infected monkeys.

When representatives from varying agencies disagree on how to handle Dr. Nancy Jaax's discovery, she realizes there are few protocols in place for containing a deadly virus on U.S. soil; an employee at the monkey research facility falls ill.

An employee at the monkey research facility falls ill, causing Dr. Nancy Jaax to fear the virus has spread to the human population; Jerry Jaax searches for a way to protect his wife; Dr. Wade Carter is obsessed with exposing the dangers of Ebola.

Dr. Nancy Jaax works tirelessly to find out why the virus is behaving differently than expected in human victims; unforeseen dangers arise at the research facility; Jaax is forced to make a choice between her family and her duty to her country.

A volatile situation inside the research facility comes to a head; Dr. Jaax steps up, but exhaustion threatens the precision needed to sterilize the threat; the press arrives, and neighbors become aware of the danger next door.