Twelve-year-old Alex has been raised by his uncle since his parents disappeared on a trip to Scotland many years ago. He’s resigned to spending the summer in Scotland with yet another relative and finds himself on a farm near the ruined remnants of an ancient castle that is rumored to be haunted. Could it have a connection to his parents’ disappearance? With three newfound friends, Alex sets out to discover the secret of a sealed cave along the rugged coast that borders the farm.