During Justus‘ birthday party in Rocky Beach, of all places, Justus Jonas, Peter Shaw and Bob Andrews come across a mysterious video tape featuring Justus’ deceased parents. With their message, they want to give their son the key to a particularly difficult puzzle. The ‘Three ???’ immediately set off for the abandoned estate of the mad inventor Terrill, which is located in a lonely forest in Northern California. It soon becomes clear that things are not quite right there and that the house seems to be under a curse.