The file above was removed from Mega (a cloud service I had been using to provide downloads) on the 20th of April 2015, after a complaint by the Church of Scientology. They are now hosted elsewhere, and you can download them again.
The OT3 level is kept secret by Scientology. OT3 materials relate the “Xenu” story. Hubbard himself claimed that the reason for this secrecy is that anyone who reads about this without proper preparation (by Scientology) will die of pneumonia. This claim is part of Scientology doctrine.
After the success of the original “Star Wars” film in 1977 Hubbard saw an opportunity to exploit the renewed interest in Science Fiction by producing his own screenplay, entitled “Revolt in the Stars”. Somewhat inconsistently, this screenplay recycles the Xenu story.
Hubbard failed to sell his screenplay (readers can judge why) and this inconsistency did not become a problem. However, the fact that he was prepared to release a ‘secret doctrine’ in a mass-market film brings his previous statements into question.