The Slaughterhouse

(Based on my own real experience as I remember it. The only thing changed for the sake of the story format are names and, of course, dialogue as I can't remember exactly what we said.)
After her step-dad decides that an abandoned pig farm he found in the woods will make a good home, 13-year-old Des is meant to spend her first weekend home alone in her new house. But, she's determined the place is haunted and calls her friend who she believes has a sense for the supernatural. Reluctantly, her friend agrees to come over after Des promises they can explore the abandoned barns. It's when they enter those barns that they realize they weren't as alone as they thought.