Crimson, the Color of Blood

After a jewel robbery goes horribly wrong and their leader, Jack, (Naschy) is shot in the head, a band of thieves goes to a local doctor for help. To save their friend's life, the criminals devise a unique scheme: Kill their worst enemy, toss his body onto a railroad track in front of an oncoming train, and use his severed head for a brain transplant! Unfortunately, the unwilling donor, the Sadist, turns Jack into a raging lunatic bent on murder and destruction!