Musician Herb McGwyer, formerly half of
folk duo McGwyer Mortimer, arrives on the remote Wallis Island off the coast of Wales, where eccentric widowed superfan Charles Heath has contracted him to play a show before a select, private audience. After winning the lottery, Charles travelled the world with his late wife Marie, who loved McGwyer Mortimer, spending all their money. They then won the lottery again and retired to the island, where Marie died five years prior to the events of the film. Charles brings Herb to stay at his home, presenting his £500,000 fee as a suitcase of cash. Charles also gifts Herb with a few things he has expressed a fondness for in interviews, including Herb’s favorite apples. Having transitioned from folk music to commercial pop, Herb intends to use the money to finance the next album in his struggling solo career. He fends off Charles's questions about his professional and personal breakup with his former musical and romantic partner Nell Mortimer. Charles reveals the makeshift "stage", a
pallet on the beach, and eventually admits that he will be the show's sole audience. Herb is surprised by the arrival of Nell, whom he has not seen in years, and her American husband Michael, whom he meets for the first time. Charles is thrilled to have reunited McGwyer Mortimer, but tensions flare over dinner when Nell, who has retired from music and now sells homemade chutney at
farmers' markets in
Portland, Oregon, discovers that Charles is paying her £200,000 less than Herb for the gig. After a heated argument, Herb storms off to his room and attempts to leave the island in the morning, but stays only after Michael confides that he and Nell need the money. Charles shows Herb and Nell his collection of McGwyer Mortimer memorabilia, including Herb's old guitar and what turns out to be a counterfeit lock of Nell's hair. After Michael leaves for a birdwatching tour on the far side of the island, Herb and Nell reconnect as they rehearse their old folk songs for a deeply moved Charles. Playing
tennis with Herb, Charles notes that the only strong aspect of his game is his
serve, since he always plays alone. Herb urges Charles to ask out Amanda, a single mother who runs the island's only shop, while Charles insists there is still chemistry between Herb and Nell. Herb and Nell bring Charles to spend a joyful "Seamen's Day" on the beach, writing wishes on
sky lanterns and releasing them at sunset. Later, Herb tells Nell that he is still in love with her, but she reveals she is pregnant and accuses him of fixating on their past. Leaving a real lock of her hair for an understanding Charles, who urges her to continue writing music, Nell departs. Lashing out at Charles, Herb packs his things, including his old guitar, and storms off in the rain. With no boat available to ferry him off the island, he leaves his bags with Amanda, who has learned about his music from her teenage son, and returns to Charles's house. Michael arrives in the morning to collect Nell's money—after Charles lied to him that the gig took place early—and lectures Herb about his pursuit of Nell and the sorry state of his musical career. When a despondent Herb wades out to retrieve one of the lanterns, Charles assumes he is trying to commit suicide and tries to save him, but Herb rescues Charles instead. Having arranged the show for the fifth anniversary of Marie's death, Charles accepts that forcing a McGwyer Mortimer reunion was a mistake and offers to pay Herb regardless. However, the message on the sky lantern reveals Charles' love for Marie, inspiring Herb to play the show and invite Amanda on Charles's behalf. Herb performs for them late into the night, dedicating a final song to Marie. The next day, Herb thanks Charles as they part ways, hugging him goodbye. After returning home, Charles discovers that Herb left the money and his guitar, signed with his real name—"Your biggest fan, Chris Pinner". Amanda arrives, dressed for a game of tennis. Motoring away from the island on a boat, Chris opens the suitcase that the money was in to reveal it now only holds his favorite apples that Charles gifted him in the beginning. Chris smiles, tosses one in his hand, and takes a big bite. As the credits play, Chris, no longer using his stage name, records a new folk song, "The Ballad of Wallis Island". ==Cast==