Two "Normal" teenagers - they cut classes, get into fights and are never far from their Walkman headsets - notice a sudden change in their fellow students. No one is able to explain this zombie-like behavior which, at the command of an unseen alien, makes them punish transgressors with merciless violence.

The Watergate Plumbers, a poorly-performing college basketball team, lose their best players one by one to death and dismemberment at the hands of a mysterious masked stalker.