Watch Santo vs. The Riders of Terror for Free: How to Stream the Movie Online at 123Movies. . After a group of violent lepers escapes from a sanitarium, - robbing several farms, residents of the town demand the the sheriff - take action. Meanwhile, a local criminal joins forces with the lepers - to commit even more robberies. As the disfigured madmen keep the - entire town indoors with its reign of terror, the sheriff has no - choice but to call on the only man who can help--legendary wrestling - superhero, Santo!