1944, Shanghai occupied area. Military agent Hu Tao was exposed during an operation and was in a desperate situation, but unexpectedly discovered that he could see the cause and effect chain of things - for every event that happened, there was a faint line connecting the cause and consequence. He tried to rewrite cause and effect, and reversed the deadlock at the cost of 'stealing' a move from his opponent. From then on, Hu Tao relied on his eye of cause and effect to move among the Japanese and puppet forces, the military command, and the underground party. He quietly changes the direction of each confrontation: letting a secret letter be delivered three seconds late, letting a key figure change the route temporarily... But every time he rewrites, he has to pay a price - or lose a piece of memory, or lose a few years of life. He must weigh the cost and victory and find the optimal solution in the puzzle of cause and effect. However, when a big conspiracy involving the entire city surfaced, he discovered that he was not only a chess player, but also a pawn in the game. Can he change the direction of the world line? Or will it be swallowed up by cause and effect?
