When 13-year-old Sullivan Carter and his younger brother, Colton, are forced to hide from school bullies in the cundy (a water conduit in Castle Eden Dene), they are attacked by a terrifying creature which goes on to haunt their dreams. Rumour has it that some older teens have been performing strange rituals at the cundy. As a result, Sullivan is convinced that he and Colton are now being hunted by an ancient creature that's been unleashed from its dark lair. When Colton begins to hear voices which draw him back to the cundy, he tells Sullivan he believes one of them belongs to their dead mother. Sullivan must reach beyond his own profound grief in order to defend Colton and himself against the wily creature. Does he have what it takes to defeat it? Or will he need to sacrifice himself in order to save his little brother?