Um, okie. So, there have been murders going around town, and these two detectives work on gathering clues, etc. But one of the detectives is actually the murderer, and he kind of just wants revenge on all the buttholes he had to deal with?
So he works with the other detective, but he sends her in circles and messed with the evidence so she cant figure out who killed these people, or who's next. However, one night he can decide to invite her over, and she sees something and gets suspicious.
There are a lot of ways to go about this though..