In 1935, there was an undercurrent surging on the beach in Shanghai. Fan Chengxuan, the low-key owner of a medicine shop, is actually the "shadow shopkeeper" who controls half of the city's intelligence. When his beloved Ma Kexi defected late at night with a top-secret list, she breathed her last in his arms, leaving only a bloody last word and a shocking betrayal trap. He must find the real traitor in the puzzle she paved with her life and protect the promise that is heavier than life.
