A biker's brother is killed while investigating the kidnapping of a young boy, the byproduct of a war between two crime families. The biker vows to get revenge by finding the kidnapped boy and destroying the two families.
Syndicate Sadists, also released under the titles Rambo's Revenge and Final Payment, is a 1975 poliziotteschi film directed by Umberto Lenzi. It stars Joseph Cotten and Tomas Milian.