In Shanghai in the 1930s, An Min, the son of a southern Yunnan tea merchant, returned from studying in Japan. He wanted to take over the family tea business and live a stable life. However, he encountered a mysterious woman during an assassination at Paramount and became involved in a spy war in troubled times. Using the "Anji Tea Shop" as a cover, he transformed from a confused son-in-law into a military intelligence agent. During the secret training in southern Yunnan, he learned to use tea codes to communicate and use the caravan route to fortune; and Shu Xin, who was beside him, was not only the sharp edge of the anti-corruption team, but also his confidant and friend in troubled times.
From intercepting the Japanese army's Yangtze River transportation information, to posing as a couple to assassinate the traitor Fu Xiao'an; from dealing with the suspicion and internal strife within the military command, to reaching intelligence sharing with Pan Hannian, an underground party of the Chinese Communist Party - their secret codes and determination are hidden in the curls of tea smoke; in the hail of bullets, the tacit understanding and perseverance of the two men are condensed. The mellowness of Yunnan Yunwu tea, the undercurrent of the Shanghai Concession, and the rumors of the Tea Horse Road are intertwined into a little person's family and country tragedy: they guard the tea shop, guard each other, and guard the original intention of "driving out the invaders and restoring the soil". In the age of blood and fire, using tea as a sheath and faith as a blade, they write their own spy war legend in the gaps of history.
