The story of Xenu is covered in OT III, part of Scientology's secret "Advanced Technology" doctrines taught only to advanced members. It is described in more detail in the accompanying confidential "Assists" lecture of 3 October 1968 and is dramatized in Revolt in the Stars (an unpublished screenplay written by L Ron Hubbard during the late 1970s). Direct quotations in this section are from these sources. (See also Scientology beliefs and practices)
Seventy-five million years ago, Xenu was the ruler of a Galactic Confederacy which consisted of 26 stars and 76 planets including Earth, which was then known as Teegeeack. The planets were overpopulated, each having an average population of 178 billion. The Galactic Confederacy's civilization was comparable to our own, with aliens "walking around in clothes which looked very remarkably like the clothes they wear this very minute" and using cars, trains and boats looking exactly the same as those "circa 1950, 1960" on Earth.
Xenu was about to be deposed from power, so he devised a plot to eliminate the excess population from his dominions. With the assistance of "renegades", he defeated the populace and the "Loyal Officers", a force for good that was opposed to Xenu. Then, with the assistance of psychiatrists, he summoned billions of his citizens together to paralyze them with injections of alcohol and glycol, under the pretense that they were being called for "income tax inspections". The kidnapped populace was loaded into space crafts for transport to the site of extermination, the planet of Teegeeack (Earth). The space craft were identical to the Douglas DC-8 with the exception of having different engines.
When they had reached Teegeeack/Earth, the paralyzed citizens were unloaded around the bases of volcanoes across the planet. Hydrogen bombs were then lowered into the volcanoes and detonated simultaneously. Only a few aliens' physical bodies survived. Hubbard described the scene in his film script, Revolt in the Stars:
Simultaneously, the planted charges erupted. Atomic blasts ballooned from the craters of Loa, Vesuvius, Shasta, Washington, Fujiyama, Etna, and many, many others. Arching higher and higher, up and outwards, towering clouds mushroomed, shot through with flashes of flame, waste and fission. Great winds raced tumultuously across the face of Earth, spreading tales of destruction. Debris-studded, and sickly yellow, the atomic clouds followed close on the heels of the winds. Their bow-shaped fronts encroached inexorably upon forest, city and mankind, they delivered their gifts of death and radiation. A skyscraper, tall and arrow-straight, bent over to form a question mark to the very idea of humanity before crumbling into the screaming city below...
Ã¢â‚¬â€œ L. Ron Hubbard, Revolt in the Stars treatment
The now-disembodied victims' souls, which Hubbard called thetans, were blown into the air by the blast. They were captured by Xenu's forces using an "electronic ribbon" ("which also was a type of standing wave") and sucked into "vacuum zones" around the world. The hundreds of billions of captured thetans were taken to a type of cinema, where they were forced to watch a "three-D, super colossal motion picture" for thirty-six days. This implanted what Hubbard termed "various misleading data"' (collectively termed the R6 implant) into the memories of the hapless thetans, "which has to do with God, the Devil, space opera, et cetera". This included all world religions, with Hubbard specifically attributing Roman Catholicism and the image of the Crucifixion to the influence of Xenu. The interior decoration of "all modern theaters" is also said by Hubbard to be due to an unconscious recollection of Xenu's implants. The two "implant stations" cited by Hubbard were said to have been located on Hawaii and Las Palmas in the Canary Islands.
In addition to implanting new beliefs in the thetans, the images deprived them of their sense of personal identity. When the thetans left the projection areas, they started to cluster together in groups of a few thousand, having lost the ability to differentiate between each other. Each cluster of thetans gathered into one of the few remaining bodies that survived the explosion. These became what are known as body thetans, which are said to be still clinging to and adversely affecting everyone except those Scientologists who have performed the necessary steps to remove them.
The Loyal Officers finally overthrew Xenu and locked him away in a mountain, where he was imprisoned forever by a force field powered by an eternal battery (Some have suggested that Xenu is imprisoned on Earth in the Pyrenees, but Hubbard merely refers to "one of these planets" (of the Galactic Confederacy). He does, however, refer to the Pyrenees as being the site of the last operating "Martian report station", which is probably the source of this particular confusion. Teegeeack/Earth was subsequently abandoned by the Galactic Confederacy and remains a pariah "prison planet" to this day, although it has suffered repeatedly from incursions by alien "Invader Forces" since that time.