When the children of American astronauts choose Herman as the good-luck name for the next Gemini space capsule, Edward Lindquist is dispatched by State Department official Colby Grant to shadow the band on tour and gather intelligence to avert a PR nightmare. Grant fears that putting the band's name on the rocket will make the world think the U.S. is, in his view, > still a colony of Great Britain.
Meanwhile, aspiring starlet Cecile Bannister hires a publicity agent and a photographer to stage photos with the band, convinced this exposure will win her a new contract. They photograph a chaotic scene during a riot at Los Angeles International Airport, and the resulting spread in the newspapers misleads Lindquist into thinking Bannister is an old friend of Herman. Bannister, in turn, suspects Lindquist is a writer and part of the band’s entourage as they sift for information neither of them truly possesses.
Herman and his bandmates, who are mobbed wherever they perform, are kept in their rooms at the Miramar Hotel by their manager Dudley Hawks before a charity benefit. Herman spots teens on the beach and yearns to be one of them, to meet the girl of his dreams and to fall in love. Louisa Page(/actor/shelley-fabares), the benefit organizer’s daughter, offers to show him the sights of Los Angeles, and after some back-and-forth, the two slip away to Pacific Ocean Park, while the rest of the group wanders the park exploring.
Believing the boys have been kidnapped, Dudley calls the police. Lindquist and Herman eventually reconnect on a roller coaster, and the scientist realizes Bannister has fed him false information. Once the misunderstanding clears, Lindquist comes clean to the band about his mission, and they agree to let Grant witness the charity performance.
During a concert that draws a nationwide crowd of teens, the publicity saga forces NASA to rethink the rocket’s naming. The tension and public pressure culminate in a decision to name the capsule after the band, restoring a sense of national unity around the mission: “Herman’s Hermits.” The delay becomes a rallying point for fans across the country, and the story builds to a thrilling climax.
In the final act, the Rose Bowl concert—before a crowd of about 50,000 fans—reaches a fever pitch. The band is whisked by a hypersonic jet to Cape Kennedy for the rocket launch and then rushes back in time to finish the show, delivering one last song before the credits roll and sealing the tale of fame, diplomacy, and teenage energy.
