Twelve-year-old Mia and her classmate Benny take a class trip to the Gruber Family's mountain ranch, where they begin to suspect something's fishy: Mysterious witching symbols appear, the Gruber's cattle falls sick, the well water turns black and the barn burns down. What the heck is going on here? Are they being haunted by an evil mountain spirit? Or is someone trying to put the Grubers out of business? Mia and Benny get unexpected support from their new classmate Johannes. Together they follow their handful of clues and leads: How did the poison the kids found wind up…