Scientology Lies

OT IV, or Operating Thetan level 4, is the fourth of the eight Operating Thetan levels. It deals with the effects of drugs on a person's whole track (entire history of lifetimes). It may be thought of as a Purification Rundown covering all of a person's many lifetimes.

Links

OT Levels described in Understanding Scientology by Margery Wakefield

Operating Thetan - from Scientology at Wikipedia