Despite being the most prominent celestial body after the Sun, the Moon has many qualities that science has yet to explain. Lunar rock samples reveal the Moon once had a magnetic field like the Earth, and seismic experiments by NASA suggest the Moon is at least partially hollow. For centuries people have observed lights, moving clouds and shadows, and even the disappearance of entire craters via telescope. Apollo astronauts repeatedly felt the presence of a "non-human intelligence" during their Moon visits, and many indigenous traditions speak of malevolent visitors from the Moon. A growing body of astrophysical and geological evidence shows the Moon is not an entirely natural world--that someone or something altered it long ago. Louis Proud explores the phases and movements of the Moon along with its ancient and mysterious features--its craters, maria, rilles, tunnels, and domes. He examines several of NASA's Apollo missions, showing not that NASA faked the Moon expeditions but that they concealed what the astronauts found there. He explains the many holes in the commonly accepted "Giant Impact" theory of the Moon's origins and reveals the evidence for a hollow, artificial Moon placed in orbit eons ago to observe Earth. Examining the deep influence of the Moon on the collective mind of humanity, Proud looks at what the Qabbalah, the tarot, and other occult traditions say about the Moon and interprets G. I. Gurdjieff's teachings that "we are food for the Moon." He investigates the Moon as a gateway to another realm, as the Purgatory of Christianity, and as the home of an alien intelligence who controls and exploits humanity. Examining the Moon from both scientific and esoteric perspectives, Proud shows the Moon is not a cold, dead rock but a rich, fascinating world just as alive as Earth.

Since his late teens, Louis Proud has suffered from chronic sleep paralysis and has undergone hundreds of such episodes, many of them terrifying but ultimately transformational and eye-opening. These experiences, he believes, allow access to the "spirit realm" and could well hold the key to a whole host of paranormal phenomena, including poltergeist disturbances, out-of-body-experiences, mediumship, spirit possession, and succubi and incubi encounters. Drawing on the work of Colin Wilson, Joe Fisher, Stan Gooch, Whitley Strieber, Robert Monroe, Dion Fortune, and a number of other paranormal experts, Proud lucidly demonstrates that many sleep paralysis experiences involve genuine contact and communication with incorporeal entities, some of them parasitic and potentially dangerous. In this comprehensive, open-minded exploration of the sleep paralysis phenomenon, filled with fascinating descriptions of his own experiences, as well as those of others, no stone is left unturned as Proud attempts to get to the bottom of the mystery.