In the middle of the withdrawal operation in Wonsan in 1950, the United Nation Headquarters is informed of a secret message that a strange disease, which seems a plague, is killing dozens of patients even a day at a hospital in Wonsan. Intelligence officials are shocked and dismayed by this message. To get the facts, a special force is organized for this secret mission. The force comprises a Korean Naval officer, American intelligence officer, and a handful of specially trained special forces troops. They successfully execute their mission with the local anti-Communist guerrilla forces' support and find that the unknown disease is not a plague. Consequently, the United Nations Command decides not to withdraw its fighting forces from the Korean peninsula.