Shi Gengtian, an old scout of the Eighth Route Army, finally got news of his long-lost son. He wanted to take his son to Shi Xiaojiang's regiment under the escort mission, but he received an urgent mission to infiltrate the Japanese army and find out the identity and action plan of the mysterious Japanese man. Shi Gengtian sneaked into the Japanese army camp as a cook, but he didn't know that the restaurant owner Lao Qiu who escaped from the encirclement of the Japanese army with him that day was the mysterious man Qiu Shanjing. Shi Gengtian fought wits and courage with the enemy, repeatedly saw through the enemy's conspiracy, and intercepted key intelligence for the Eighth Route Army. His son Shi Laifeng was taken into the team by Shi Xiaojiang. During the operation, he met Shi Gengtian many times but did not know each other's identity. Shi Laifeng even misunderstood Shi Gengtian as a traitor and often confronted him. Shi Gengtian finally found out the identity of the mysterious man and found out that the content of the K plan was to build a gold mine. According to Shi Gengtian's intelligence, the Eighth Route Army went through many difficulties and found a way to blow up the mine. The father and son who had misunderstood and entangled with each other finally recognized each other after twists and turns. In a desperate battle, the father and son joined forces to successfully crush the enemy's K plan.