After being forced to give her baby boy up for adoption, Glasgow teenager Kelly Ann decides to go on a cross country hike through the Scottish Highlands with a group of friends. Kelly Ann's ex - boyfriend Lee then appears uninvited in an attempt to rekindle their relationship. Things do not go to plan however when Kelly Ann & Lee find an abandoned baby in the ruins of an old castle. As the teenage group attempt to get the baby to safety, a vicious, wolf-like beast appears from the darkness and begins to stalk the group, picking them off one by one. The group soon realise that they have to kill the creature or be killed themselves.
