Answer:
you open the door and it's cold and you look around and see that it's empty
Step-by-step explanation:
They'll need to know why and who was keeping you out. You'll need to slowly build the story up, you always walking past and maybe trying to open it. You can introduce yourself and your characters through conversation and describing the mood and setting. Easy to to in 1st Person
You're the protagonist. Minor characters maybe your friends you tell about the door or the person warning you to not go inside
the rest you'll have to make up or you'll get caught for plagiarism