With the arrival of a new and mysterious inmate, known as El Coco, fear grips the place: stormy nights, unexplained deaths, and an atmosphere charged with tension. Desperate authorities turn to a unique group of comical prisoners to uncover the truth. Can they save themselves from this sinister creature?

Amparo, a mysterious woman, offers a large payment to quickly cremate a young woman named Lucia. When the funeral home owners refuse, they later discover the body has vanished and, in panic, give Amparo another person’s ashes instead. She pays and leaves, unaware that this mistake will lead the undertakers into the worst trouble of their lives.