When a virulent flu epidemic sweeps through Moscow killing hundreds of thousands of inhabitants, Anya and her husband Sergei decide to flee to a lake in the far north of Russia where they hope to sit out the epidemic. But as the wave of infection expands from the capital, they encounter obstacles, hazards, and aggression, with near escapes from death as they try to navigate their way through a harsh Russian winter, with diminishing supplies of petrol and food. And their troubles multiply as Sergei agrees to takes on unwelcome guests and Anna struggles with her own feelings of hostility and jealousy.