Anything Can Happen

Imagine this.
You walk in winter at ten in the morning just to return your library book, the crunchy snow drenching your legs while the chilling air bites into your lungs.
You get to the library.
You fall asleep while reading a book.
When you wake up, you find everyone gone and realise you're trapped in the dark and gloomy library.

What do you do?

Find out in this short story;)