During the Spring and Autumn Period and the Warring States Period, the famous military strategist Sun Bin and Pang Juan became close friends. They went down the mountain after finishing their studies. The teacher hinted that Sun Bin said that Pang Juan was narrow-minded and could not be intimate, but Sun Bin did not care. Knowing that Sun Bin was smarter than himself, Pang Juan was jealous, for fear that Sun Bin would seriously threaten his position, so he became murderous and secretly framed Sun Bin for having an affair with a foreign country, so as to embarrass himself. Sun Bin, who was kind-hearted, was kept in the dark. When his knee was cut off, he devoted himself to writing Sun Tzu's Art of War for Pang Juan. It was not until one of Pang Juan's servants bravely stood up and spoke that Sun Bin learned the truth and woke up from a rude awakening. Later, Sun Bin escaped from the clutches of fraud and madness and finally got revenge. It is precisely because Sun Bin mistakenly made such a bad friend as Pang Juan that he escaped death, but after all, his body and mind suffered great trauma.