Mysteries of the Unknown is a series of books about the paranormal

Paranormal

Paranormal is a general term that designates experiences that lie outside "the range of normal experience or scientific explanation" or that indicates phenomena understood to be outside of science's current ability to explain or measure...

, published by Time-Life Books from 1987 through 1991. Each book focused on a different topic, such as ghost

Ghost

In traditional belief and fiction, a ghost is the soul or spirit of a deceased person or animal that can appear, in visible form or other manifestation, to the living. Descriptions of the apparition of ghosts vary widely from an invisible presence to translucent or barely visible wispy shapes, to...

s, UFOs, psychic powers

Parapsychology

The term parapsychology was coined in or around 1889 by philosopher Max Dessoir, and originates from para meaning "alongside", and psychology. The term was adopted by J.B. Rhine in the 1930s as a replacement for the term psychical research...

 and dream

Dream

Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not definitively understood, though they have been a topic of scientific speculation, philosophical intrigue and religious...

s. The series was very successful for Time-Life Books. Within 15 months of the series' release, it had broken every sales record for the company.

There were 33 volumes in the series:

• Alien Encounters Discusses extraterrestrial encounters and possible abductions.
• Ancient Wisdom and Secret Sects Includes details on Hermeticism and secret societies.
• Cosmic Connections Discusses mankind's long curiosity about the influence of celestial bodies.