In Shanghai in the 26th year of the Republic of China, the rain during the rainy season entwined the neon lights of the French Concession, weaving an invisible spy war network. Gu Yinmiao, a piano teacher who returned from studying abroad, is actually an intelligence agent codenamed "Nightingale" by the military command, and is responsible for the secret mission of transferring the arms list at the dock. When she reunited with her former classmate Su Fuying on a rainy night at Paramount, her calm disguise was shattered - the notoriously ruthless chief of the Secret Service Section 76 was the rumored murderer of her brother's execution.
The emerald brooch hides a micro transmitter, the sapphire cufflinks are engraved with emergency codes, and the arms list in the piano resonance box is intertwined with the traitor's blood contract to form a mystery. Gu Yinmiao took the music box left by her brother and deciphered the secret words among the keys of the piano studio. Little did she know that Su Fuying had hidden a gun pointed at her under her white cheongsam - or a shield to protect her.
From the cheongsam fight at Paramount to the life-and-death confrontation in the dock warehouse, from the mystery of the fake list to the secret fight over the safe at the Japanese consulate, the two women move step by step amid suspicion and temptation. When the torture chamber No. 76 Encountered the military commander's assassination order, and when the brand of "traitor" was engraved on their loved ones, they were shocked to realize that each other's guns were always aimed in the same direction: those jackals in human skin, and the haze hanging over the Huangpu River.
The moment a broken jade brooch reflected the red five-pointed star, all misunderstandings and hatred turned into the sharp edge of the same hatred.
