Professor Morbid Grimsby is an evil genius who has won the prestigious "Meanie" award six years in a row; to guarantee a seventh, he plots to eliminate all laughter by getting rid of the Sunday funnies, with the aid of his henchman
Brutus.
Popeye is given a job as captain of the Professor's
yacht, the
SS Hilarious, and all the characters from the humorous comic strips are informed that they have won a free ocean voyage upon this boat. Once out at sea, the boat is pulled to a remote island by the Professor's
tractor beam, and in the chaos Popeye's stash of
spinach is lost at sea; thus, he and all the passengers are prisoners of the Professor. Being a huge fan of the Sunday funnies, the
President of the United States takes action by calling together the heroes of the adventure comics to rescue the prisoners. The rescue attempts go wrong, and the adventure characters also end up as prisoners. The prisoners eventually decide that the only way to free themselves is to make the Professor laugh, to convince him that the world needs laughter. They put on a
talent show which fails to have an effect, but then the younger characters get him to laugh by showing him his own reflection in a
mirror while he's trying to scare them; the Professor has a change of heart, and decides to let everyone go. At that moment, however, a
volcano on the island begins to erupt; the Professor uses his
submarine to get the comic characters off the island, but it gets stuck in a cavern. Popeye finds his spinach in the water, eats it, and frees the submarine. The story ends with the comic characters and the Professor being treated to a party on the
White House lawn; they're told that the President will join them shortly. Unbeknownst to the guests, he is actually at that moment enjoying the comics page of his newspaper. ==Voice cast (uncredited)==