1940, Shanghai.
Paramount's popular dancer Gu Manjun has two secrets: first, she is an agent of the underground party of the Chinese Communist Party codenamed "Nightingale"; second, she is not the real Gu Manjun.
Ten years ago, the real Gu Manjun was killed in France, and the organization arranged for her to lurk in her place. This secret should have been buried forever, until she received the task of assassinating Tang Xiaocheng, deputy director of the Wang Puppet Agent Headquarters.
On the night of the assassination attempt, Tang Xiaocheng said something to her: "You are not afraid of death - you are evaluating me, like a hunter evaluating his prey."
He saw right through her. But he didn't reveal it.
Soon, Gu Manjun discovered that Tang Xiaocheng had a photo hidden in Tang Xiaocheng's hand from ten years ago. The person in the photo was her - or in other words, the real Gu Manjun. And the way he treated her was not like a captor and a prey, but more like... An old friend who had been waiting for ten years.
When a traitor appeared within the organization and the codename "Nightingale" was exposed, Tang Xiaocheng covered her up in his own way. Who is he? What happened in France ten years ago? And does the organization she has always been loyal to hide any secrets from her?
Under the deepest disguise lies the most dangerous truth.
