Natural Enemy

Also known as Hate - Haß, Der Feind in meinem Haus, 杀人夜

“Some people are just born enemies”

A businessman (Donald Sutherland) has a hotshot young new partner (William McNamara). What he doesn't realize is that his new partner is the son of his second wife, adopted into an abusive family at birth and now a raving psychopath out to murder his natural mother for whom he blames the miseries of his lifetime.