In 1966, a ship floating on the North Atlantic Ocean was the base camp of a rock radio station loved by British listeners. Carl (Tom Sturridge), who dropped out of school due to drug abuse, was sent here by his mother Charlotte (Emma Thompson), and met Quentin (Bill Nighy), The Count (Philip Seymour Hoffman), Dave (Nick Frost) and other people who love music and advocate freedom. On the other hand, senior government official Sir Alistair Dormandy (Kenneth Branagh) decided to try to ban illegal radio stations. As the government put pressure on the sponsors of the radio station, the income of the radio station continued to decline. At this time, Gavin (Rhys Ifans), who has been abroad for two years and now enjoys international reputation, decided to return to the radio station and solved the problem of the radio station. However, due to Gavin's return, some new problems have emerged within the radio station...