There are complicated and confusing cases, and the murderers are all related to each other. The cases seem to be unrelated, but in fact they all have something in common. Is it planning? Or is it purely a coincidence? Insufficient evidence allowed the real murderer to escape again and again. A chance encounter gradually spliced the pieces of evidence into a big net that enveloped everyone, and the final murderer turned out to be an unrelated person.
Concept: Love cannot defeat justice but it can defeat time