The Captain of the ship receives bad news from his second-in-command: there are four stowaways onboard, as the crew found out when they heard them singing harmonies down in the hold, and a note has been found insulting the Captain himself. A group of sailors are despatched there to investigate, not realising the stowaways (played by the four Marx Brothers) are hiding in empty barrels labelled herring, and the crafty quartet would have gotten way with their scheme if the containers were not lifted up to the deck, leaving them crouched on the floor. But they are not going to be caught so easily, and make good their escape - a very long escape that lasts the rest of the voyage.
Monkey Business marked the Marx Brothers' move to Hollywood and a film specifically written as a movie rather than an adaptation of a stage show as their previous efforts had been. The results were given a lukewarm reception from the critics and tastemakers overall, but audiences loved it, and it became known as one of their funniest efforts, for the first half at least as consensus was it wound down by the finale and the kidnapping plot. Even so, the drop off in quality was far from a precipitous one, and it remains one of their funniest productions, too short to outstay its welcome and the shipboard antics are indeed some of the most hilarious scenes of their era, maybe of any era.
Really, the plot hardly mattered, with the team's writers (including legendary wit S.J. Perelman) acknowledging that and cramming in as many gags as possible into the brief running time. That first half detailed the Marxes avoiding the Captain and crew, outsmarting them at every turn with physical lunacy such as the puppet show Harpo gets mixed up with (one of the most sidesplitting sequences ever filmed, and not only because of the face he pulls while pretending to be a puppet), or Groucho discombobulating anyone he speaks to with by use of his doubletalk and barrage of puns. Well, everyone except Chico who is on his own private wavelength and immune to Groucho's dialogue. Also along for the ride was the actress who would be the leading lady in three of the Marx comedies, Thelma Todd.
This might be the best showing she ever offered, since if we couldn't have Groucho outwitting Margaret Dumont (she was considered for a role, but lacked sex appeal in the studio's opinion) then the next best thing was the talented Thelma, an adept comedienne and foil who had beauty and comic ability, though now is best recalled for her mysterious death in 1935 of which a few unresolved solutions have been theorised. Watching her fall about the set with Groucho, and perhaps more importantly keep up with his rat-a-tat delivery, and you appreciate how important it was for the reactors to the Marxes' humour to play it commendably straightfaced. Leave the laughter to the audience: in one scene Groucho gets a few chuckles from the cast and it almost kills the gag.
Needless to say the immigrant humour of the ship sequences endeared the boys to a very substantial audience who could relate to the way they got one over on the authorities, but that appeals to anyone who has ever felt downtrodden by the powers that be or even society at large. When the four of them are trying to get through customs by pretending to be Maurice Chevalier it's both highly amusing for its silliness, and barbed for its basis in a real situation that millions had seen, and were going through, it's little wonder they became heroes of the counterculture a few decades later with their relentless irreverence. Once on dry land, the storyline featuring a returning gangster's daughter (Ruth Hall) getting kidnapped from a society ball does get in the way of the jokes, and some never got on with Chico's trick piano playing or Harpo's harp, but the tunes they play are possibly their best and it's always captivating to see the placid concentration on the latter's face, the only time he's calm. Winston Churchill loved his film and would screen it to get him through the Blitz, quite an endorsement for a classic of its kind.