A secret autopsy demonstrates the bizarre progression of the mystery virus, prompting Jim to make a startling confession. Eph and Nora race to find the father of the youngest victim of the plane tragedy, but someone unexpected beats them to it. Ansel, in the grip of disease, takes desperate measures to protect his family.

After warning Kelly to leave the city with Zack ahead of the spreading plague, Eph is arrested by the FBI. Eichhorst has one final job for Gus, while Setrakian realizes that the coming eclipse is the tipping point for virus infection and the beginning of the end.

Setrakian, Eph, and Nora formulate a plan to track down the Master using Jim as bait. Eichhorst and Setrakian’s pasts are revealed. At the Luss home, Neeva struggles to protect the children while encountering a mysterious stranger whose help she may not want.

Eph races to safeguard his family, only to learn that Kelly is missing. Dutch reveals her role in Palmer’s plan, and Gus is forced to make a difficult decision about Felix.