In the Season 1 finale, Alan and Walker battle the Scythe to save the world from disaster.

In the second-season premiere, Drs. Peter Farragut and Sarah Jordan are joined by Kyle Sommer when they battle a new deadly virus on a mysterious wooded island.

The CDC team continue to investigate the island; at the same time, they discover Peter's brother, Alan, is a member of Brother Michael's cult, and his warnings for them to leave the abbey fall on deaf ears.