Plot

One place. One day. Two men. The place is a polar research station on an island in the Arctic Ocean, inhabited now only by Sergei and Pavel. One day when Sergei is out angling, Pavel picks up a radio message that he daren't communicate.

A polar station on a desolate island in the Arctic Ocean. Sergei, a seasoned meteorologist, and Pavel, a recent college graduate, are spending months in complete isolation on the once strategic research base. Pavel receives an important radio message and is still trying to find the right moment to tell Sergei, when fear, lies and suspicions start poisoning the atmosphere...—Koktebel Film Company

Meteorology student Pavel "Pasha" Danilov is spending the summer as an intern at an isolated, Soviet-era weather station on a remote Arctic island with only the older, experienced geophysicist Sergei Gulybin for company. Their sole job is to collect the weather and tide statistics every four hours on antiquated equipment, which they do in shifts, and report the readings by radio to the state meteorology center. Pasha is respectful and friendly, but he is afraid of the gruff Sergei, who is condescending to him, as he resents Pasha's temporary stay and is jealous that he knows how to operate their only computer.

Sergei takes the boat on an unauthorized fishing trip for a few days, and tells him not to mention this. When the radio operator urgently requests to speak with Sergei, Pasha dutifully makes up excuses why he cannot come on the radio. Eventually Pasha is told to take down a radiogram that Sergei's wife and young son have been "gravely injured" in an accident, although it is apparent they've been killed. He is told that a ship is headed to get them and instructed to simply give Sergei the message and then "leave him alone." The sad news keeps Pasha awake, but when he does sleep he oversleeps; the data goes unrecorded. Seeing Sergei's boat, he hastily grabs the logbook to fill in fake numbers, and in doing so knocks his radiogram under the desk. When Sergei comes ashore with the trout, he is in a good mood. He tells Pasha a warm story about his wife craving salted trout during her pregnancy. Pasha starts to say something, but Sergei interrupts and teaches him how to properly fillet a fish.

Once inside, Sergei quickly figures out that the Pasha made up the numbers in the log and explodes in anger, dragging Pasha inside and berating him. He tells him that the station has been continuously occupied since 1935, and that no matter how bad the conditions got, never had anyone just faked the numbers out of sheer laziness, and that now all their work is worthless. He accuses Pasha of being a "tourist" in the Arctic in order to write a pointless essay, "How I Ended This Summer" (a play on the clichéd "How I Spent My Summer Vacation.") Sergei tells him an intimidating story about the time one geophysicist apparently killed the other due to their strained relationship.

The frightened Pasha does not tell Sergei about his family and temporarily sabotages the radio. When Sergei leaves to get more trout, Pasha is told that the ship is stuck in ice, but that a helicopter will instead come before the weather worsens. Pasha, carrying a rifle, heads to the lagoon to meet the helicopter, but the pilot cannot see the flares due to the heavy fog and flies away. Pasha then notices a polar bear, which begins to chase him. He runs away but eventually trips and falls down a steep embankment.

Pasha wakes up in Sergei's boat. As they disembark, Pasha tries to confess to Sergei that he needs to tell him something but Sergei ignores him. Pasha finally blurts out to Sergei that his family is dead. Sergei turns around and comes toward him, and Pasha, frightened and with an injured leg, falls to the ground. Thinking Sergei is going to attack him, Pasha fires at him but misses. He then gets up and runs away while Sergei picks up his gun and fires at him, and then keeps shooting into the air.

Pasha takes up residence in an old abandoned cabin. He wakes up to hear Sergei outside and hides, still afraid. Sergei calls to him and says he wants to talk to him. Sergei, who is carrying his rifle, hears Pasha step on something that makes a large cracking sound. Thinking Pasha fired at him, he fires his own rifle. The terrified Pasha runs away. Pasha, freezing, huddles by an old isotope beacon to keep warm before realizing he has exposed himself to radiation. He sneaks into the cabin when Sergei is away and tries to contact the main station for help but cannot reach anyone. Starving, he steals Sergei's fish and nearly chokes to death on a fishbone. He screams and curses Sergei. He hangs fish up on the isotope beacon; he later sneaks back into the cabin and replaces Sergei's stash of fish with the contaminated fish.

One night Sergei sees the disheveled Pasha looking in the cabin window watching him eat the fish. He signals to Pasha to come inside, and then invites him to sit down and have some fish. He says the Academic made it through the ice after all and will be there in three days. Pasha confesses that the fish has been contaminated. Sergei says nothing, but goes to vomit up the fish he has just eaten. Pasha checks the cupboard and sees Sergei has eaten all of the contaminated fish. Sergei returns and says only that they don't have to tell anyone what has happened.

The Academic arrives and Sergei tells Pasha he plans to stay on the island. Pasha threatens to tell what has happened to force Sergei to get medical help. Sergei insists he needs to be there alone and embraces Pasha.