Hell Swarm (2000)

Billy Sabbath is a cop, who was on an undercover assignment with his partner. Things were going fine until his partner for reasons that he only knows started shooting everybody, and was about to shoot Sabbath when Sabbath killed him. An investigation reveals that Sabbath had an ulterior motive for wanting to see his partner dead. He was tried and sentenced to death and was about to be executed, when a secret group led by a man named Bludhorn, rescues him. They tell him that the man he killed was not his partner, at least on the inside. He had been taken over by a species they call The Phylum. It seems that they lived on Earth before man, and somehow they were wiped out. But now those who survived are planning to take back the Earth. Bludhorn wants Sabbath to join them but unfortunately Sabbath can't tell anyone he's alive including his wife. When Sabbath does what he was told not to do, The Phylum find him and tell him that they will harm his wife unless he tells them who saved him and what do they know about them (The Phylum). Bludhorn's people save Sabbath, and they tell him that his wife is now part of The Phylum. Sabbath doesn't believe them and when he tells them that he's going to get his wife, Bludhorn orders him terminated but the person Bludhorn assigned, hesitated allowing Sabbath to escape. So now Sabbath is working on his own; at the same time Budhorn and his people are trying to find out what they are planning.