The author must increase the conflict and tension to have a satisfying denouement that the reader can believe in and be happy about. We can have conflict between characters if the investigator and the villain come face-to-face. Or the villain and another victim. Or the investigator and authorities, if the detective isn’t law enforcement.
|How dark are the woods?|
I find it a “fun” part of the process to increase the tension and conflict – maybe because there are so many options.
What makes you keep reading a mystery title?