A good detective novel typically has a complex mystery to solve, interesting characters, and a plot that keeps you guessing until the end.
For a detective novel to be compelling, it should have a well-crafted mystery that challenges the reader's thinking. It often includes elements like red herrings, motives for the crime, and a resolution that makes sense but still surprises. Good character development of the detective and suspects is crucial too.
Well, a detective novel usually features a clever detective, a puzzling crime, clues scattered throughout, and maybe some unexpected twists and turns. The setting and supporting cast also add to the overall appeal.