In 1943, behind enemy lines in North China, the Eighth Route Army's sharp knife squad, led by Zhao Tiezhu, attacked the "Eagle's Nest Fortress" in Heifeng Ridge at night in an attempt to save compatriots and obtain information on the Japanese army's "decapitation plan." They broke through thunder formations, solved puzzles, battled wits and courage with the mysterious "shadow guards" and traitors, and got involved in the grudges between Zhao Tiezhu and his junior brother. In the end, they smashed the conspiracy at the cost of blood and fire, and wrote a thrilling tragedy of the war behind enemy lines.
