Ling Chenfeng (played by Chu Chien-hsueh) is the sergeant of the New Territories North Emergency Team. During a mission, Ling Chenfeng's actions were obstructed by a man named Guan Dingmin (played by Wang Haoxin), and a fierce battle eventually broke out. Ling Chenfeng's father Ling Hai (played by Luo Lelin) died in an accident, which made Ling Chenfeng very self-blame. However, what she didn't expect was that she actually had the ability to turn back time. She returned to three days before the incident with high morale, hoping to save her father's life. However, things were not as simple as Ling Chenfeng imagined. When she returned to the past, her every move would affect the future. In the end, Ling Chenfeng successfully rescued his father, but accidentally discovered a shocking conspiracy of collusion between police and gangsters. Ling Chenfeng, who was full of justice, resolutely returned to the past again, but discovered the unknown kindness of his enemy Guan Dingmin.