Jack (Himesh Patel) is an unknown singer. Except for his good friend Ellie (Lily James), no one believes that he can become famous. In an accident, Jack was shocked to find that he was teleported to a parallel world. In this world, the Beatles never existed, which means that Jack is the only one in this world who knows the band and has heard their works. So Jack began to perform the Beatles' songs and took them for himself. Sure enough, the songs of the greatest band in history soon made Jack famous and wealthy, and he became the most popular music creator in the world at that time. However, after the initial excitement subsided, Jack found that he could no longer create his own music and could only become a poor repeater. This was obviously not the result he wanted, so Jack began to find ways to return to the normal world.