1942: Operation Nightingale

In 2025, Chen Hui, an employee in the Security Bureau archives, is sorting through a faded file from 1942 about the Shouyi Alliance of Jinmen when a sudden electrical failure accidentally sends her back to 1942, a war-torn era when the Japanese army ravages Jinmen, the puppet regime aids and abets them, and the Shouyi Alliance fights back.

After she transmigrates, Chen Hui is wearing a European-style dress and carrying the distinctive pocket watch of a clerk at the Japanese army's intelligence agency. She finds herself in the old city of Xiguan, just after it has been bombed by the Japanese. Drawing on the intelligence skills and quick thinking she developed at the Security Bureau, she improvises, posing as a Western expatriate named Su Wan and claiming she is going to stay with her uncle, who works for the Japanese intelligence agency. This lets her evade questioning by a Japanese patrol for the time being.

Knowing how hard it is to survive in a time of chaos, and determined to uncover the truth behind the attack on a Shouyi Alliance contact point mentioned in the file, Chen Hui decides to infiltrate the Japanese intelligence agency stationed in Jinmen and aid the resistance. She finds Lu Yan, a core member of the Shouyi Alliance's Jinmen communications station, and, after explaining her intentions, takes the codename “Nightingale.” They agree to use a nightingale mark as a secure signal for operations and intelligence exchanges.

With Lu Yan's help, Chen Hui strengthens her cover identity and forges documents. After intensive training in French etiquette and the intelligence agency's office procedures, her fluent French and convincing disguise help her pass the many tests set by the agency chief, Jichen, and secure a job in the clerical department.

She carefully gathers the Japanese army's most important intelligence, waiting for a chance to assassinate its officers and puppet troops' leaders. With every step carefully planned and danger all around her, she uses her intelligence and courage to navigate the chaotic times. Under the name “Nightingale,” she carries hope through the darkness and writes a thrilling legend of espionage.