March 31, 1970. Flight 351 departing from Tokyo airport on a domestic route is hijacked by representatives of the Japanese Red Army and demanded to fly to Pyongyang. The Japanese government is unable to cope with the situation, and the South Korean secret services decide to take advantage of it. The plan is to get ahead of the North and intercept the radio signal, and then convince the terrorists to land on the territory of South Korea, having previously disguised the Seoul airport as Pyongyang airport.