In the early spring of the 26th year of the Republic of China (1937), a murder occurred in the French Concession in Shanghai that shocked the whole city - "Nightingale", the top singer at the Paramount Ballroom, was hanged in a box in a strange manner. Young detective Shen Yanzhi is entrusted with the investigation, but in the process of solving the case, he falls into an inescapable time loop: every time he gets close to the truth, he is pulled back 72 hours before the crime and starts over. As the number of cycles increases, he discovers that this is not only a murder case, but also a fateful trial about memory, atonement and identity.
