The plot concerns a squad of six British Army soldiers training in the Scottish Highlands. Expecting to carry out a routine training mission, they find the savaged remains of a special forces squad who were part of the same training exercise. The single survivor makes cryptic references to what attacked them. Unseen antagonists make their presence known in the background, and the soldiers retreat. The group encounter a zoologist who takes them to a lonely house. As darkness arrives, the house is surrounded by the attackers: to the soldiers' incredulity, these are revealed to be werewolves.