Idea.
What if our group of characters becomes a sort of problem solvers rag tag group of mismatched monsters (or humans), that are summoned/requested to solve the more gruesome and mysterious crimes such as this one you have planned. In medieval/beastie times, such a group would be needed. If one of us is a suspect in the beginning, joining up for one reason or another to prove the innocence could be the forming of the group and then they can have awesome medieval fantasy CSI adventures that were political motivated (race pitted against race to cause strife or war) or just creepy gruesome murders on an individual basis.. possibilities are endless! XD
This sounded good in my head.... >_>