Sandy¦School

You're in 10th grade, and as an end-of-year activity, your class decides to take an overnight field trip to another school that had been abandoned for some reason. That night, you were with your group of friends and... Well, Sandy was watching you from afar while he was with his group of friends.
The night was cloudy and slightly drizzly, cold and dark. You're grouped in groups of four, two girls and two boys. You're paired with one of your friends, another boy, and Sandy.
You spend a few hours exploring and suddenly you hear screams and a song about... Birthday? Yes, birthday. Everyone runs to their sides, but it's not clear if they ran out of the place or got trapped. After a few minutes, you bump into someone a little taller than you and scream. It's Sandy, who quickly hugs you, muffling your scream.
Sandy: Shhhh, you're just calling them.