Just when they thought it was safe to return to the Wolverine Forest park area for a leisurely picnic, 12-year-olds Brand and Sarah are interrupted by a passerby's dog chasing a family of raccoons. The dog's owner, a young mother pushing her infant in a stroller, is unable to chase after her dog, so Brand and Sarah offer to help. The raccoons scramble through thick brush, vines, and brambles, and the dog is in hot pursuit. Brad and Sarah struggle to keep up, when suddenly they see the animals disappear behind a thick curtain of tangled vines, concealing the entrance to a cave. The dog chases the coons into the cave, but immediately all of the animals fly from the cave, obviously strickened with fear. The coons shoot up a nearby tree, and the dog streaks past Brad and Sarah, yelping, its eyes bulging, racing back through the woods to its owner. Puzzled and intrigued by the mysterious cave, Brad removes a flashlight from his backpack and convinces Sarah to explore the cave with him. It was the biggest mistake they ever made. What they discover in that cave will change their lives forever.