In a small Mexican village a funeral is in progress for Fabian Mendoza (Gabriel Alvarez). At the gravesite his widow, Maria (Sara Cabrera), insists on having the coffin opened so that she can take one last look at her husband. After that the men begin to cover the coffin with dirt. Before they get more than a few shovels’ full thrown on top, Mendoza’s son Javier shows up wanting to see his father’s body. When the casket is opened again the body is gone. Doctor Morales (Arturo Corona) is deeply concerned. He believes the body may contain a plague and unless the body’s found the whole town could be in danger.

Javier tells his uncle Nachos Mendoza (Manuel Donde) that he is going to ask a detective to investigate. The detective is Gaston Santos (Gaston Santos). Gaston is a cowboy detective that, along with his trick horse Moonlight, solves crimes. Javier shows up at Gaston’s place dying having been attacked on the road. He whispers something to Gaston and dies.

In the meantime a monster comes out of the swamps and kills the grave digger that was at Fabian’s funeral and pulls him under the water.

Gaston calls on a friend to help him in his investigation. Squirrel Eyes (Pedro de Aguillon) ferries his way through the swamp in a small boat. The fish monster comes up underneath his boat and pulls him into the water. Squirrel Eyes manages to get away and swim to shore. When Gaston rides up Squirrel Eyes tells him about the fish monster but the creature has gone.

While Gaston is talking to Squirrel Eyes someone tries to shoot him. The man is chased but he manages to get away. Squirrel Eyes takes Gaston to Dr. Morales, who patches him up.

Gaston finds out that Maria is blind and has been for months. Since she was blind when Fabian was buried she can’t say for sure that there was a body in the coffin when the grave digger opened it up just before Javier arrived. Gaston tells Javier’s Cousin Julie (Manola Saavedra) about Javier's death and asks her not to tell Maria yet. He still has some investigating to do before he can formulate a theory and gather enough evidence about what is going on in town. Gaston slowly begins to put things together. There is a conspiracy in town and Gaston needs to find out who all the players are.

“Swamp of the Lost Monsters” AKA “Swamp of the Lost Souls” AKA “El Pantano de las Animas” was released in 1957 and was directed by Rafael Baledon. It is a Mexican mystery, western, horror, suspense movie. What isn’t this movie?

Besides the disappearing body there are trick horses, fist fights, insurance fraud, murder, bad comic relief sidekick singing, stock footage of fiestas and rodeos, a big red fish monster that can shoot a harpoon gun and knows Morse code and an underwater rubber knife fight. It’s all wonderful. Included are the usual bad acting, dumb dialogue, cheap sets and pure camp. This movie is not for the squeamish. You need to be a fan of bad movies to appreciate it.

This was one of the movies dubbed into English and released in America by K. Gordon Murray. Many of the names were Americanized during the dubbing. The bad dubbing adds to the camp value.

The film is in color and about 75 minutes long. The only copy I could find is in real bad shape and is either black and white or so washed out that it looks like it’s black and white. It’s a television copy so it’s all chopped up leaving the run time under an hour. Unfortunately it’s all I could find. It is on DVD but it’s hard to find.