How does she end up naked?

At the beginning

19 year old Jojo had just entered his house. He had spent all day delivering conscription notices and putting up propoganda as his injuries stopped him from joining the war effort. He threw his bag to the ground and sat in his living room, he was about to nap when he suddenly heard a noise from upstairs.

'Mum, is that you?' He shouted up the stairs, getting no response. He went to the coat rack and didnt see her jacket or shoes. He pulled out his knife and crept up the stairs to investigate.

He first looked in his mothers room before proceeding to his late sisters room, where he noticed something strange, a set of dirty clothes folded on the bed. He got closer to have a look when he heard noises from the bathroom. He crept towards the door and slowly pushed it open and he saw the intruder.

She was a young girl, just turned 18 with brown hair and a pretty face. As he opened the door all the way she was about to climb out of the bath and he saw her, completely naked and she was staring right back at him