L. Ron Hubbard used the term Incident in a specific context for auditing in Scientology and Dianetics: the description of space operatic events in the Universe's distant past, involving alien interventions in past lives. It is a basic belief of Scientology that a human being is an immortal spiritual being, termed a thetan, trapped on planet Earth in a "meat body".
Although Incidents can be any incident anywhere, Hubbard's writings described some in particular, set in Earth's prehistory. Many of them first appeared in Hubbard's book What to Audit (later retitled A History of Man).
In his writings and lectures, Hubbard describes Incidents said to have occurred to thetans during the past few trillion years. Most of these followed a consistent pattern, wherein a hostile alien civilization captured and brainwashed free thetans. Often, instances of implantation are termed Incidents, while the subject of the implants are often termed Goals. Some Incidents are simply unusual and traumatic events, whereof the memory is said to linger for trillions of years. According to Hubbard, only Scientology's methods can remove the resulting neuroses.
"There is a Before Earth and a Before MEST Universe in all banks. The incidents are not dissimilar. They consist of the preclear being summoned before a council, being frowned down, being sent elsewhere than where he was... the council's intent is to reduce the person downscale in order to get a more obedient colonist."
The Body Builder Incident took place around fifty million years ago and variants of it are said by Hubbard to have recurred often, wherein the thetan was forced to fight with his own "attention units" and build a MEST body from them.
"Bodies in pawn result" from a "very gruesome experience" in which:
a fellow is grabbed, hypnotized, shoved into an electronic field, and then told he is somewhere else. And so he departs—most of him—and goes to the new location while still being under control of the implanters. He picks up a MEST [physical] body in the new location and starts living a life there, while still having a living body somewhere else. The implanters can keep his original body alive indefinitely, and control the thetan through it. If the thetan tries to flee, the hypnotizers simply cause pain to the original body, still alive in a vat of fluid, and he is immediately recalled. That's a BODY IN PAWN. It's a second body you may have, living somewhere else, right in present time. But the second body is not under YOUR direct control.
(Source magazine #105, pg.39, 1997; see also Hubbard, Research and Discovery Series vol. 10)