Josh collects horror comics and he loves to terrify his brother, Paul, and his stepsister, Mandy, with scary stories - the more gruesome, the better! So when the three are sent to Wales to stay with their grandparents, Josh starts to spin a spooky yarn about the strange Balwen Black Mountain sheep that live around Grampy's farmhouse. He says that Rhys the Fleece - a legendary, devilish shepherd - guards them, and will grant a magic wish to anyone brave enough to stay out in the valley all night long . . . and survive. So when a ruthless local developer threatens to build on Grampy's land, Paul decides to put the magic wish to the test!