The answer is in the detail

“The answer is in the detail” is the guiding principle passed from Yifu to Li Yan and recalled at a crucial point in the investigation of the murdered women. It links a family inheritance of lateral thinking to the detectives’ practical work: evidence matters not only for what it says on its own, but for the pattern it reveals when examined without distraction.

Origin in Yifu’s teaching

Li remembers Yifu, his uncle and mentor, as someone who taught him to think laterally and to look for truth in details. Li had lived with him for more than ten years in the police apartment block in the Ministry compound. After Yifu’s death, Li continues to feel his influence during investigations, imagining his advice at his shoulder when setbacks make him doubt himself. Others measure Li against Yifu’s reputation, crediting his successes to his uncle’s influence and treating Yifu’s achievements as a standard Li may not match. The principle is therefore both professional instruction and a demanding personal legacy.

The saying is attached to an intimate household memory as well as to police work. Yifu’s former room has become Xinxin’s room, and she asks Li to tell her stories about the smiling man in the photograph on the wall. Li makes time for those stories. His recollection of Yifu thus joins attention to the past with an act of care in the present: the uncle’s lessons continue through what Li remembers and passes on.

A method tested by the investigation

The principle becomes practical when Li considers the possibility that the crimes involved the live autopsies of eighteen women, and perhaps more victims still unidentified. He recalls Margaret’s earlier, partly joking suggestion of a psychopathic surgeon, but the team’s discussion also tests how far any single explanation can go. Detective Dai points out that the procedures would have required another participant to administer sedatives and operate a manual resuscitation bag. Li recognizes that this detail changes the working hypothesis: the killer may not have acted alone, and the case may involve a coordinated group rather than a solitary offender. He sets speculation aside in favor of the immediate task of identifying the victims.

That exchange shows the principle as more than a call to collect minutiae. A particular practical requirement—the need for assistance during the procedures—forces investigators to revise an assumption about how the crimes were committed. Attention to detail can widen the inquiry, but it also requires distinguishing a plausible inference from an established fact and keeping the investigation directed toward evidence that can be pursued.

Margaret’s recognition of the overlooked connection

Margaret’s return to the principle comes through grief and self-reproach. After hearing that Chai Rui, a young woman who had worked as a club hostess, had a daughter, Margaret thinks of the women whose bodies she had examined and of the lives and relationships cut short by their deaths. The newly learned fact makes her reconsider what she has been looking for. She blames herself for having too much information and not seeing what was obvious, then tells Li that she has found the answer to a riddle.

The exchange recalls a bus-driver riddle Margaret had posed. Its point, as she explains it, is that attention can become absorbed by numbers and names while the answer sits plainly in the question itself. Looking again at the anatomical evidence, she tells Li that she has recognized a connection among the victims that cannot be coincidence. The available scene establishes the shift in her thinking, not the complete identification of that connection: the decisive change is that she has begun asking what the victims share rather than treating each detail in isolation.

Recurrence and significance

The expression connects Yifu’s advice to two different moments of casework. Li applies it when a procedural detail challenges the assumption of a lone perpetrator; Margaret applies it when a victim’s personal history makes her reconsider the mass of information she has been processing. In both instances, the principle works through correction: investigators must notice what their first reading left out and allow a concrete fact to reorganize their understanding.

Its recurrence also gives the phrase a personal charge. For Li, the lesson is inseparable from his longing for Yifu and the pressure of living in the shadow of his uncle’s reputation. For Margaret, the renewed insight follows an emotional encounter with the victims’ individual lives. The expression therefore does not promise that the answer will be easy to find. It insists that careful attention—to evidence, to overlooked connections, and to the people behind the case—is what makes finding it possible.