Joaquin Phoenix plays Freddie Quell, an alcoholic former sailor. While serving in the Navy during World War II he developed the dangerous habit of mixing drinks using medicine cabinet supplies and the occasional solvent. Now in the 1950s he has become a sullen drifter given to occasional violent rages. After nearly killing a migrant worker who sampled one of his concoctions he takes refuge on a yacht docked in a nearby port.
The captain of the yacht is Lancaster Dodd (Philip Seymour Hoffman) a flamboyant and charismatic cult leader with some wealthy and influential followers. Dodd is quite obviously based on L. Ron Hubbard, the founder of Scientology. (The producers insist that any resemblance is purely coincidental.)
Dodd takes a liking to Freddie and makes him part of his inner circle, much to chagrin of Dodd’s wife (Amy Adams) and some of his other followers. It seems pretty obvious that Freddie is not terribly bright and potentially dangerous.
Dodd is a fascinating character. He does seem to be a con artist–even his son accuses him of “making it up as he goes along.” However he seems to really believe his own fantastic doctrines. (Maybe the most dangerous con artist is the one who is sincere.) His sincere belief that he can help Freddie is his main justification for keeping him around.
(Other possible reasons might include his fondness for sampling the results of Freddie’s chemistry experiments and maybe an unacknowledged homosexual attraction.)
After this buildup I was expecting an over-the-top ending like There Will Be Blood, an earlier film by director Paul Thomas Anderson. Instead it just sort of peters out. This movie might have been more satisfying if it had given us more of Lancaster Dodd and less of Freddie Quell, who (regardless of the source of his problems in this life or previous ones) is fundamentally an unpleasant and unimportant character.