Detectives will often pursue a particular line of investigation based on available clues, information or even a hunch. All that matters is solving the case as quickly as possible and to do so, they'll follow whatever appears most likely to facilitate doing so. Sometimes, after a while, their favored strategy doesn't produce the result they thought it would. This means they must pursue a different line of enquiry. In an area of your world, to 'get to the bottom' of a particular matter, it appears you might have to do the same. A new 'investigative' strategy looks set to be more effective.