The were 4 members of a small local Detective group called "The H.A.T.S.". But 2 were gone from the group. The Grey Hat was found unalive near an alley way with his face being destroyed, and the faded Blue Hat's status remains unknown. The only thing we knew was that he was strangely ill with a disease that was to expensive to treat. So, he attempted to cure himself, which could probably ended his life. It couldn't be confirmed because he was nowhere to be seen.
@Grinnyboi also press space