Secrets come to the light and unlikely alliances are established; at the same time, Alan and Walker take on a dangerous mission to destroy what's left of the NARVIK virus.

Alan and Julia travel to an abandoned satellite station in a last-ditch effort to call for help. Once there, they come across the truth behind Hatake's plan and Julia's condition. Meanwhile, Dr. Jordan makes a startling discovery of her own, which could mean a cure for cancer.

Peter leads the Vectors in a desperate final attempt to spread the virus, while the CDC scientists work together and successfully create a cure just as their lives come under threat from Ilaria Corporation's deadly mercenaries.