Mr. Williams (Bill Nighy) is an ordinary man who has worked in an office pushing papers for years, never really getting anything done. When he gets terrible news that he has a terminal illness, he realizes that the dreams of his youth have come to nothing. He tries to tell his son and daughter-in-law about his diagnosis, but doesn't find the opportunity, which makes him feel even more alone.
Not knowing what to do with the time he has left, Williams bumps into Miss Harris (Aimee Lou Wood), who works in his office but needs a reference from him to apply for a different job. He takes her to Fortnum's for lunch to write the letter and her wonder and excitement at the simple pleasure of being in such a fancy restaurant opens his eyes. At the eleventh hour, he takes it up himself, despite his poor health, to turn his dull life into something wonderful.