Etzel Cardeña is a scientist who studies things like parapsychology, which is the study of things like telepathy and precognition. He looks at things like experiments done with people to see if they can sense things that are happening in the future, or read another person's thoughts. He tries to figure out whether or not these things are real, and if so, why they happen. He also looks at other topics like dreams and out-of-body experiences. Etzel Cardeña is like a detective who solves mysteries about the mind!