He sat outside the door and waited for history to repeat itself. The very first night, he tried going inside. That had been easy; discovering he was intangible, he simply walked right through the door. Recognizing the apartment once inside, he quickly searched for him.
He was sitting on the bed, a pistol in his lap. Unfortunately, that was when he found out he was also invisible and inaudible. No matter what he did, he was helpless to stop it. After the inevitable, he found himself back in his own room in the present.
Every night, it happened again. And every night, he was helpless to change anything. So this night, as so many nights before, he just sat in the hallway and waited. Once again, he heard the gunshot and a body slump to the floor. And again, he found himself back in his room. It was over for now, but it would repeat the next night. And every night.