In communist East Germany, General Streck plans a monumental cultural festival to distract the world from a sinister plot to reunite Germany under his country’s rule. When conductor Leonard Bernstein cancels, American rock and roll star Nick Rivers, who had a number one hit with the song, “Skeet Surfing,” steps in as a last-minute replacement. Arriving at an East German checkpoint, Nick insults the ruthless Colonel Von Horst, despite the pleas of Martin, his manager, to remain diplomatic. Meanwhile, a British spy named Cedric has slipped into the country. At the cultural festival, Cedric makes contact with an undercover agent, who informs him that the East Germans are forcing scientist, Dr. Paul Flammond, to build a new weapon, but the doctor’s whereabouts are unknown. Cedric receives instructions to meet “the Torch,” leader of the Resistance, at the ballet that night, but the East Germans trap Cedric in a scrap metal compactor before the rendezvous. In the formal dining room of Hotel Gey Schlüffen, Nick arrives for dinner and receives a tie and jacket from the maître d’ before being seated. Meanwhile, Hillary Flammond, the beautiful daughter of Dr. Flammond, is being pursued by police and escapes into the dining room. As she is about to be escorted away, Nick convinces the maître d’ that Hillary is his date. The two get to know each other while they dance and order dinner. As the maître d’ introduces a special impromptu performance by a singer, Nick mistakenly believes he is being called on stage and does not realize the introduction was intended for Biletnikov, a high-ranking Communist official. Although Biletnikov and General Streck are annoyed and leave, Nick thrills the rest of the diners with a performance of the hit 1950s song, “Tutti Frutti.” When Nick returns to the table, Hillary has left. Back in her hotel room, she is surprised to see Cedric, who has escaped from the compactor, but can barely move, as his body is encased in metal. Despite the risk, she takes Cedric’s place and attends the ballet to meet the Resistance leader, hoping he can assist in locating her father. Nick is also at the performance and when he sees a man aiming a gun at Hillary, he throws the assailant over the balcony, and helps the young woman escape. Since he is a VIP guest in the country, Nick believes he is protected and stays behind, but East German authorities detain him at Flurgendorf prison for tossing a secret police agent over the balcony. Martin assures him that he will be released before Friday’s concert, which is being transmitted live to eighty-five countries. However, General Streck and Colonel Von Horst interrogate Nick and appear to have no interest in letting him go until he reveals information about the attack on their agent. From his jail cell, Nick finds an escape route and stumbles into a dungeon laboratory where he encounters Dr. Flammond. The doctor is being forced to create a terrible nuclear weapon called the Polaris Mine, which must be completed by Sunday or the East Germans will kill his daughter. When Nick accidently damages the weapon, police hear the commotion, enter the laboratory, and recapture him. As Nick stands before a firing squad, Streck receives orders to delay the singer’s execution until after the concert. During the performance, the audience of mostly young women screams wildly for Nick, until he is suddenly lifted above the stage and led away by Hillary Flammond. When she shows Nick a photograph of her father, he recognizes the scientist he saw at Flurgendorf. After evading East German police, Hillary and Nick proceed to a Swedish bookshop owned by a member of the Resistance and arrange to meet “the Torch” the following day. In the meantime, they spend the night in the loft above the bookshop, and Hillary tells Nick about being shipwrecked on a desert island as a child. Her only companion was a boy named Nigel and together they learned to survive, until one day he mysteriously disappeared, and she was eventually rescued by a passing ship. After Nick serenades Hillary, they make love. In the morning, Hillary and Nick are hidden in a horse-drawn wagon and taken to the farm hideout of the Resistance. When “the Torch” emerges, Hillary recognizes him as her long-lost Nigel, and they warmly embrace. Nick informs the Resistance that the Polaris Mine will be ready on Sunday, and gives them Dr. Flammond’s location. As Nigel and his men prepare to take action, Hillary tries to console a dejected Nick and convinces him to stay and help the cause. After East German soldiers ambush the Resistance hideout, Nigel assembles the group at the local pizzahaus and accuses Nick of being an imposter and traitor. To prove he is the real Nick Rivers, the singer turns on the jukebox and does an impromptu performance. Once again, the young women scream wildly. That evening, Nick joins Resistance fighters as they parachute toward Flurgendorf prison. During the operation, Hillary confesses her love to Nick, but she believes in the Resistance cause and does not want to abandon Nigel. Disguised as a cow, Nigel and one of his men access the generator and cut power to the prison, allowing the rest of the group to sneak into the facility and rescue Dr. Flammond, while Hillary waits with the getaway vehicle. However, Nigel is revealed as the real traitor when he tries to sabotage the operation, and kidnaps Hillary. As the others safeguard the doctor and take him to a British plane set to depart that night, Nick confiscates a motorcycle and prepares to rescue Hillary. At a bridge, Nick intercepts Nigel’s truck and grapples with the traitor as the two men fall into the river below. In an underwater fight, Nick overpowers Nigel, and he and Hillary hurry to rendezvous with Dr. Flammond. Meanwhile, the doctor anxiously waits for his daughter and refuses to leave without her, despite the pilot’s insistence they must take off before dawn. Just in time, Nick and Hillary arrive on the motorcycle, and she runs to embrace her father. Hillary is initially hesitant to leave East Germany and abandon the Resistance, but Nick convinces her to join him in America.