They hide to see him come out only to see the Sheriff come out building coffins, and stage props. On their way back to the jail they see Romero sneaking around and into the undertaker's. The gang soon hears Emilio and Esteban call for help, saying they're trapped in jail. When they do go in they find a poster with El Scaryachi on it. When they get back to Emilio and the gang, they turn off the water with the value, and Emilio goes into the tunnels telling them no to go into their shack. He chases them off a bridge causing them to crash into a barn, When El Scaryachi leaves, he drops the Sheriff's badge. El Scaryachi then rides on a parade float and continues the chase. When they get to the mausoleum they are chased by El Scaryachi, they avoid cacti and coffins. Shaggy and Scooby follow Lila's scent to a cave where they find scraps of paper that says the ingredient they need is the trident chilies from the top of the cemetery, inside the mausoleum. Shaggy and Scooby throw the value over the gate and Emilio gives them the key to the cemetery gates. When they get to the entrance they meet Esteban's twin brother Emilio, who says the cemetery is for gravekeeper's only, he asks them to get the value to turn off the water in the well so he can save his brother from jail. When they give it to him he asks for them to take a picture of him with it. After the gang defeats them Romero asks them to find his harmonica that Costington hid. When they find him, Romero is being attacked by zombie brides.
He then asks the gang to find Romero because he has the key to the cemetery. He says that monsters have been appearing ever since a harmonica started playing in the cemetery, then El Scaryachi and his bandido army scare the town away. Then they head off to Costington's mansion, when they get there Costington is surprised to meet them even though he called them earlier, But Costington says that he hasn't had a phone installed yet.
GET TO.MANSION SCOOBY DOO SPOOKY SWAMP FREE
Shaggy and Scooby defeat them, get the gunpowder, light the fireworks, and free the gang. Suddenly an out of control parade float crashes into town and skeleton seniors attack. Shaggy and Scooby record the Sheriff's talk about gunpowder locked away in the Saloon. Shaggy and Scooby manage to get out and Fred tell them that the Sheriff is talking in his sleep about fireworks. Confused the gang starts to ask the Sheriff questions which causing him to fall asleep. The Sheriff says that the gang are the ones causing trouble claiming they're El Scaryachi. The gang find themselves in prison with another man named Esteban, who says that the Sheriff is loco and falls asleep if he gets too crazy. The gang drives to El Muncho where they find the place deserted and suddenly they're stopped by a Sheriff who arrests them.
Back at the headquarters Velma receives a phone call from Costington to go on holiday much to Shaggy and Scooby's delight. She says that the stew is for them but it's missing some ingredients, so Shaggy and Scooby decide to help her, she instructs the two to go to El Muncho. They follow it where it leads deeper into the swamp and meet a girl named Lila. Shaggy and Scooby go outside where they smell a tasty aroma. Scooby and Shaggy make a sandwich but it soon gets ruined by Velma on accident. They even run into their old friend Costington. They find the town deserted because of the fact that it's being haunted by day of the dead monsters. To get ingredients for Lila, Shaggy and Scooby get the gang to go to El Muncho.