Kaitlin - …I wondered what was behind the door…

I was all alone; mum and dad had nipped out for five minutes. Then I heard someone knock on the door, I thought it was mum and dad. I opened the door and... no one was there! So where was the noise coming from? Someone must be in the house with me! I started to get scared - I wondered to myself, who is in the house with me? I went around looking in every room and behind every door. Every time I opened a door, I wondered what was behind the door but nothing was there. Was it my imagination?