RE: When a young detective gets challenged by a killer, he will have to ask help to his wise mentor with whom he had fought hard.
INTENTION: must find a killer?
OBSTACLE: his pride?
You need to push in on both of these.
1. Why is it so important he find this killer? (I know he’s probably on a rampage or whatever.) Perhaps he’s steadily targeting detective’s family or something? Detective challenged by killer is also quite cliche and neutral. You’ve gotta spin that and introduce something new to that idea.
2. The obstacle isn’t that strong just yet. Or perhaps not specific enough. Why is it so hard to ask for help? Maybe the wise mentor is a former detective turned killer/convict. (Hmm – too Silence of the Lambs, but you get what I’m saying.)
3. Give this detective a real Sophie’s choice. A dilemma. I mean – lives are on the line. This guy would ask for help regardless of past history/pride, etc.
Maybe mentor killed his family or something?
Anyways – hope you get something from this. Good luck!