Delivery boy Shen Xinghe is trapped in today - an ordinary day when he should have passed by Qin Ya, the forensic ex-girlfriend. Until an explosion occurred on the other side of the city, news of Qin Ya's death came, and the cycle restarted. He was forced to spend countless identical 24 hours, using his extreme familiarity with the city's streets and the slight changes in each delivery, to intervene in a serial murder investigation related to her like a ghost. He gradually discovered that the key to the cycle was closely connected with his wrong accusation back then. Saving her not only means breaking through the murderer's elaborate ritual, but also means that he must use this infinitely repeated day to deliver an apology that is three years late to her heart on time.
