John L. Sullivan is an incredibly successful director of Hollywood comedies. Like so many successful creators of humor, however, Sullivan wants to do something more dramatic because dramatic means serious. Sullivan wants to be taken seriously and so he sets to making a film titled “O Brother, Where Art Thou?” The film will be a raw, brutally honest and dramatic examination and analysis of the widespread poverty that is gripping the nation as a result of the Great Depression. Sullivan’s value as a studio property is enough to convince the studio head, Mr. Lebrand, pursue the truth about the downtrodden by heading out to meet them undercover on the open road.
As Sullivan starts off on what is supposed to be an incognito journey in the guise of a hobo thanks to studio costumes depicting what a studio concept of a hobo looks like, a “land yacht” appears that equipped with a doctor, reporter, chauffer, etc. He manages to convince them to leave him well enough alone to his own devices, but after hitting the road solo with nothing but a thumb for fare he still manages to wind up right back where he started from in Hollywood, USA.
Thinking that “O Brother, Where Art Thou” might just be a pipedream, after all, a disconsolate Sully (as his hobo persona is known) walks into a diner to get a cup of Joe with the last dime he has in the world. Or so he would like to convince the pretty blonde girl who really is down on her luck but still takes such pity on him that she buys him breakfast. Afterward, things get really weird when Sully and the blond girl are actually arrested for stealing Sullivan’s own car. After his servants bail them out, they wind up back again at the same place he started: his luxurious Hollywood mansion.
The blonde girl convinces him that he’s never going to be taken for one of the great unwashed as long as he is trying to pass himself as a Hollywood hobo and then further talks him into needing her along for the trip in order to keep from landing back where he started. So onto a train they hop and head off across the country where they stand in soup lines, make their way through the shantytowns where the homeless are forced to live and attend missions where food only comes as reward for having sat through evangelical sermons. By the time they reach Kansas City, Sully is sure he has what he needs to make his movie and be taken seriously.
At the same time, a romance has started to blossom between the director and the girl. A problem: the director is still married to a money-grubbing wife in no mood to divorce him and lose all the pleasures that come with a Hollywood lifestyle. Especially since the marriage was a tax shelter in the first place. The night before he is to head back home to Hollywood, Sully is handing five dollar bills to the needy when he is robbed, stripped of his I.D, knocked out cold and tossed onto a freight car. The thief is hit by the train and Sullivan awakes up the next day finding out he now is forced to really the live the life of the downtrodden with no instant get out back to Hollywood free card.
And so John L. Sullivan embarks upon his real journey of discovery. Calling himself Richard Roe as the result of a rather harsh blow to the noggin, he eventually winds up in a labor camp where after he finally regains his memory, he is promptly beaten by a sadistic warden for exercising his Frist Amendment rights which he discovers do not apply within a prison labor camp environment. Sullivan’s only chance of surviving in the harsh world of the reality of being Sully is by putting his trust in an older prison trustee. After a sweatbox punishment for an outburst caused by a newspaper obituary about himself.
While attending the screening of a movie for the convicts at black church, the congregation and the cons all give in to the humorous antics of Mickey Mouse and, for the brief period of time in which the cartoon plays out at least, they forget all the misery of their lives and live in the moment of laughter and a sense of community. Eventually, Sully joins in the laughter, unable to ignore the fact any longer that especially when things get too serious to ignore anymore there is a need for comedy and humor and laughter. Determined to get back to Hollywood and apply this epiphany to what he does best—making funny pictures—he confesses to being the murderer of filmmaker John L. Sullivan.
Meanwhile, back in Hollywood, USA, the blonde girl is working as an actress when she sees the photo of the confessed killer and brings it to the attention of the studio heads. Sullivan is released from the prison camp and welcomed back to the world of movies where anything is possible. Such as the fact that his wife/business-partner married his business manage upon the assumption that he was dead thus allowing him to marry for love. With the blond girl as his future wife, John L. Sullivan sets to work on the next act of his life: making exactly the same kind of films that turned first act into such a success. Because, after all, “There's a lot to be said for making people laugh. It isn't much, but it's better than nothing in this cockeyed caravan."