Officials of the Chicago Municipal Bus Company are worried that cross-town bus 5111, driven by Algy Shaw and Wellington Phlug, has been stolen. In fact, the bus is on its way to Los Angeles with playboy Tommy Layton and his bevy of beauties aboard. Arriving at the Seaside Yachting Club, the group relaxes until private detective Kendall enters and arrests the two bus drivers for grand theft. The drivers manage to escape the detective, then sneak into a nearby theater where they hide in the dressing room of Marco the Magician. Disguised as Marco, Algy burns up the arrest warrant, with the assistance of the dumbfounded detective. Back at the club, Tommy mistakenly kisses Joan Marshall, the sister of his main competitor in an upcoming yacht race, and she accuses him of stealing her brother's crew. Meanwhile, Kendall re-captures the two bus drivers, but Wellington makes a wrong turn on the way back to Chicago, and the bus ends up in the Los Angeles harbor. Later, Tommy learns that Joan has tricked his crew into returning to her brother's ship. In return, he abducts her and hires the fugitive bus drivers to work as his crew. Once at sea, Tommy asks Joan to declare a truce, only to discover that she has rigged the compass and that they are hundreds of miles off course. After ten days lost at sea, the quartet finds land. The group explores the island, and the bus drivers find a native village. Wellington is mistaken by the villagers for the "hero" who will help them re-conquer their haunted temple in the mountains, and Luana, Chief Kolua's daughter, tells Wellington that he must marry her, much to the chagrin of Whaba, her warrior suitor. Meanwhile, Tommy and Joan find the hut of Varnoff, a treasure-hunter pretending to be an archaeologist. Varnoff and his gang then plot to use the shipwrecked quartet in order to rob the haunted temple of its sacred jewels. After Varnoff's men fake a volcanic eruption, Wellington is ordered to prove himself by entering the temple. At the same time, Tommy and Joan search Varnoff's hut and discover his true occupation. The two are captured, however, before they can warn the others. Wellington, too, is captured by Varnoff's men as he enters the temple, and they demand that he give them Kolua's sacred ruby. Wellington manages to escape his captors, and with Algy's aid, knocks most of the crooks unconscious. Meanwhile, Tommy and Joan break free of their bindings, but when Tommy gets into a struggle with Varnoff, Joan mistakenly hits the playboy in the head and is taken captive once more. Wellington sees Varnoff escaping in a small motorboat with Jane and gives chase. Using the sharp end of a swordfish as a weapon, Wellington jumps into the boat and apprehends the treasure-hunter. As the quartet prepares to return home, Luana gives Wellington a "thank you" kiss, making him so hot that steam rises when he jumps in the water.