In London, Iris Simpkins(Kate Winslet) writes a wedding column in a newspaper and nurtures an unrequited love for her colleague Jasper Bloom(Rufus Sewell). Near Christmas, she is informed that Jasper is engaged to marry another colleague, and her life turns upside down. In Los Angeles, the movie-trailers maker Amanda Woods(Cameron Diaz) has just split with her unfaithful boyfriend Ethan(Edward Burns) and wants to forget him. Through a house exchange website, Amanda impulsively swaps her mansion for Iris' cottage in Surrey for the holidays. While in Surrey, Amanda meets Iris' brother and book editor Graham(Jude Law) and they fall in love with each other. Meanwhile, Iris meets her new next door neighbor the ninety year old screenplay writer Arthur(Eli Wallach), who helps her retrieve her self-esteem, and the film composer Miles(Jack Black), with whom she falls in love.