No trace to be found

A high-end hotel with a majestic appearance is actually a terrifying house with frequent supernatural incidents. Several bizarre murders occurred one after another. The rich boss died violently in the hotel bathtub, but no trace of the killer was found at the scene. Is it some kind of supernatural power or is there another hidden secret? As the case goes deeper and deeper, not only is there a lot of mystery behind it, but it also triggers the protagonist's torture from the depths of his soul...