CDC pathologist Dr. Alan Farragut (Billy Campbell) and his team, which includes his ex-wife Dr. Julia Walker (Kyra Zagorsky) and the lovely Dr. Sarah Jordan (Jordan Hayes), arrive at the Arctic Biosystems base on a mission to investigate a strange retrovirus, and come face to face with unimaginable horrors.

Dr. Farragut (Billy Campbell) and his team try to deal with the infected victims of Peter’s (Neil Napier) attack and contain the virus as rebellion starts to erupt at the Arctic Biosystems base.

The team thinks they’ve got the virus contained but nothing at the Arctic Biosystems base is as simple as it seems-deadly secrets and intrigue fester and spread as quickly as the virus, and no one is immune.

As Alan (Billy Campbell) risks killing Peter (Neil Napier) in a desperate effort to cure him, Walker (Kyra Zagorsky) teams with a mysterious young researcher to survive their quarantine. Jordan (Jordan Hayes) discovers her Rapid Response test isn’t working.

As Alan’s (Billy Campbell) controversial cure leaves Peter (Neil Napier) clinging to life, the unchecked virus forces Jordan (Jordan Hayes) to make a devastating decision. Walker (Kyra Zagorsky) discovers the surprising truth about her new ally, while Daniel (Meegwun Fairbrother) squares off against Balleseros (Mark Ghanimé).

After leaving Balleseros (Mark Ghanimé) to die, the mystery surrounding Daniel’s (Meegwun Fairbrother) connection to Hatake (Hiroyuki Sanada) is revealed. As he works to save Peter (Neil Napier), Alan (Billy Campbell) struggles with his feelings for both Walker (Kyra Zagorsky) and Jordan (Jordan Hayes).

Hatake rescues a “cured” Walker from Constance Sutton’s (guest star Jeri Ryan) mercenaries and Daniel discovers his true origins.

Constance Sutton (Jeri Ryan) holds Walker prisoner after her true relationship to Hatake is revealed, and the vectors launch an attack and snatch Peter’s body.

Unlikely alliances are formed and secrets are revealed as Alan and Walker undertake a dangerous mission to destroy the remaining vials of the NARVIK virus.

In a last ditch effort to find help and a cure, Alan and Julia go to an abandoned satellite station discover a shocking secret that reveals Hatake's ultimate goal and the reason why he has developed the deadly virus.

The Vectors start working together to hunt down the uninfected as the CDC develops a risky cure and a band of assassins from Ilaria secretly infiltrate the base.

The uninfected are hiding in a secret bunker on the base as the CDC attempt to retrieve the canisters with the virus and the cure while the Ilaria assassins capture Hatake and force him to chose between which one of his children they will kill first.

Alan (Billy Campbell) and Peter capture the assassin Scythe and demand to know the whereabouts of Julia’s (Kyra Zagorsky) mother. Balleseros confronts Hatake (Hiroyuki Sanada) about the missing Inuit children, while Anana and her brother learn of Daniel’s fate. Concerns that the virus is in Ilaria’s possession again forces Alan and the team off the base to search the world in order to retrieve it.