Getting there

Ron went over to open the window, but just as he did so, he frowned and then pretending as if nothing had happened, he slowly closed the window. Then he walked over to Karuman and said in a voice only the two of them could hear, "Uncle Karuman, someone had come into our room through our window."

Karuman nodded in appreciation and said, "How did you know?"

Ron said, "Because when we left, I tied a strand of hair to the window. But now, the window is not open, but that strand of hair is broken. Someone must have come in here."

Karuman said, "Continue to check if there is anything amiss in our room."

Hearing this, Ron went around and checked. He definitely would not have lost anything, because everything they brought was in Ron's Storage Ring. Karuman himself also had one. Everything in the room belonged to the hotel itself. Ron searched and found nothing, so he shook his head.