Through the centuries, two species war with each other over the human race. One needs mankind's blood to survive; the other needs human love.

In the past, two knights track the fanged creatures to a village where all the people are slain. One of the knights will not survive the confrontation.

In the present, a federal air marshal sits on a plane surrounded by the fanged ones. She knows them all too well, being the survivor of a village massacre centuries before.

In the future, a platoon of space marines responds to a distress call only to find the research station overrun with the fanged. All but one will die and he will take many with him.