In the desert area of Hat Creek, cows are found partially devoured and the farmers believe that a wolf is attacking the cattle. The alcoholic Sheriff Annie Flynn is called by the local farmer Rob Horn to witness the remains of an animal to request reimbursement from the government and for an accident with a tank truck that is blocking the road.
A new super train is built when a meteorite crashes near by, releasing a tiny creature. Once it kills and consumes everyone on board the train, it begins to grow and multiply into hordes of different creatures.
