In Shanghai in 1941, Li Wanqiu, who hid a gun in her cheongsam, became the most absurd time traveler - when she opened her eyes, she turned out to be the same-named idiot spy of Wang Puppet No. 76. Everyone thought she was the distant niece of Li Shiqun who only knew how to eat melon seeds and visit Yong'an Company. Unexpectedly, the secret monitoring system in her mind makes the information spewed out by her red lips more deadly than a gun: Mei's secret talks fall into her ears with pearls in her hair, Yamashita Tomoichi's smuggling ship is full of life-saving medicine for the underground party, and Wei Guohua, an underground party member who looks exactly like her ex-boyfriend, is drawing her into a life-and-death gamble that spans the military, the Japanese and puppets, and Hongyan. When the monitoring distance exceeded 100 meters, the bloody tinnitus could no longer tell whether it was a warning from the system or a heartbeat that was breaking apart in troubled times.