Lin Xingran, a young doctor, returns home to investigate her mother’s murder. Disguised as a family physician, she infiltrates the household of Master Fang, a wealthy suspect, but becomes the prime suspect herself after his sudden death. When Jiang Beichen, her former lover and now the lead investigator, takes on the case, old tensions reignite. As they uncover the truth together, a shocking discovery turns their world upside down.