Many think that the Marx Brothers didn't start their prolific film career until the era of the talkies. These people are unaware of the existence of the Brothers' 1921 "real" film debut, Humor Risk, (aka Humorisk). The film was only shown once and received confused/mixed reviews. Groucho Marx was reportedly so ashamed of the film that he destroyed the only copy, although many have disputed this claim.
The film has never been seen outside its original showing. There are no surviving stills, very little is known about the plot, and Groucho never said much about it. If the claim of him destroying the only copy of the film is true, then this movie will simply never again see the light of day.
This is the only missing Marx Brothers film. It would take 8 more years and the invention of the talkies for the 4 brothers to find true success.