What's behind the door ?!

Some months ago, my parents went to a wedding, and I had to stay at home with my litter brother. He felt asleep just after ten o'clock p.m. , and I stayed listening to music until almost midnight. Then I slept and I had a dream that seemed to be real.
In the dream, I knew that there was a group of thieves trying to get into my house. Then I run desperately trying to close all the doors and windows. Suddenly I heard a noise of lock opening, and my heart speeded up. I woke up  frightened, but I realized that it had been a dream and that my parents had just arrived home.