Afghanistan. 1986. A column of Soviet military armored vehicles is moving along a mountain road from the border towards Kabul. It is being covered from the air by attack helicopters. The way of the column lies across the only bridge in these parts. Afghan mujahideen are well aware of this and under the guidance of American instructors are preparing an operation to seize the bridge and destroy the Soviet equipment blocked in this case. At this time, a Soviet geological expedition in the mountains is subjected to a night attack by dushmans. The Afghan guards scatter, and the geologists decide to leave for Kabul. On the way they are informed about an approaching military convoy, with which they will be much safer to get to Kabul. The only thing they do not know is that they have long been included by the mujahideen in the operation to seize the bridge.