Hubbard describes "how 'Teegeeack' (Earth) came to be populated 75 million years ago by 'thetans' (souls) when the evil ruler Xenu of the Galactic Federation cast them into volcanos and blew them up with a hydrogen bomb to solve his local overpopulation problems."
http://www.mystae.com/streams/gnosis/otiii.html
WTF, I knew scientology was stupid but I didn't know it was that stupid. Man Tom Cruise really must be a looney.