Courtney and her twin boys, Zach and Dylan, have moved into a seemingly idyllic secluded old house in an attempt to start a new life. But the building has a secret: it is the scene of a gruesome ritualistic murder which bears a striking resemblance to a series of family slayings that have taken place over the past fifty years. A private detective investigating the recent massacre of a famous author and his family is led to Courtney and her children, whom he believes will be the next victims. As he pieces together the mystery behind the murders he uncovers an ancient myth that means the killer might be someone - or something - more evil than anything he could have imagined.