Calpuina is a night-watchman in a wharehouse, a perfect job for him. When some thieves break in and steal some crates, El Santo is after them because they are using the wharehouse for diamond smuggling. Capulina hinders their capture. Then he decides that he will put on a wrestler's mask and help El Santo to caputre the crooks.

Mario Moreno portrays a professor in this movie. A small town in the middle of no where requests the school Mario Moreno is working in for a teacher. He ends up going to give the town a hand. When he arrives he comes to know the corrupt leaders who through out the movie try to make him leave. Although he is being harassed you can see how much he cares for the kids and their circumstances. He deals with problems by using his hilarious comments.