From the notes of Detective Morris:

My new mission was to go to the ghost palace to find a big diamond. I had no desire to go to this damn place at all. You might think I was scared, but it wasn't at all. Of course, the my boss did not deserve anyone more than me. So I decided to go to this damn palace. Unfortunately, it was much more nonsensical than that. Wandering ghosts and an annoying rat keep hitting me. So finding diamonds was a big disaster for me and you have to see what happened to me...