As a contagious illness, panic and looting ravage Moscow, a thrown-together band of families and neighbors forms a shaky alliance for survival.

The group's frantic escape is disrupted by a costly mistake and human threats. Karma acts quickly after a betrayal, and a final destination is chosen.

Sparks fly between Polina and Misha. A brutal attack puts a life at risk. Some shelter in the storm is shaken by a horrifying discovery next door.

Discovering someone missing, the caravan doubles back and comes upon a good samaritan ... and some horrifying children. The disease reaches the group.

An infection leads to a house divided, and a line is crossed by Ira and Sergey. Flashbacks reveal pain in Sergey, Polina and Marina's pasts.

After Boris prays, a blessing arrives — along with more heartbreak. Ira and Sergey struggle with their secret. Safe havens prove anything but.

Marriage vows make new beginnings. Ira exposes damning secrets from Anna's diary. Pavel grapples with hard choices. A happy reunion is short-lived.