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

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

Strangers, both kind and cruel, change the journey's course, and romance blooms in unexpected places. An angry mob causes chaos and a tragic mistake.

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

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.

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.

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.