Lou Clark is an Average Jane from a small town in England. She worked at café until its owner abruptly announced that he was shutting the place down, leaving her jobless. Bummed, Lou goes job hunting until she lands a gig as a caretaker for a paralyzed man named Will Traynor.
Will is a young business executive and extreme sports enthusiast whose life was forever changed two years earlier when he was hit by a motorcycle while crossing the street, leaving him almost completely paralyzed. His mother, Camilla, tells Lou that her job will be to monitor him at all hours of the day, even though he already has a professional taking care of his medical needs.
Unfortunately, Will is a total jerk at first. He seems bitter. With time, however, he slowly warms up to Lou, and their relationship grows closer and closer. That is, until Lou learns the truth about why she was hired: after a previous suicide attempt, Will made his mother promise to take him to an assisted suicide facility in six months to end his life. Lou's job has actually been to make sure he doesn't hurt himself before then.
Although Lou is shaken by this revelation, she has a plan: she'll take Will on a series of excursions to show him that life is still worth living. Some of these trips don't go well, like one ill-advised jaunt to the horse races, but some are truly eye-opening, like a romantic night at the symphony. The big trip comes near the end of the six months: an all-expenses paid vacation to Mauritius, a small island off the coast of Africa.
It's a magical experience. Lou is amazed by the beauty of this exotic place—not to mention her growing feelings toward Will. On the final night of the vacation, Lou kisses Will and declares her love for him, saying that she knows about his plan but wants him to be with her. Although he loves her, too, Will says that he's going through with it. Furious, Lou ignores Will when they return home.
Eventually, Lou relents and decides to share Will's final moments with him at Dignitas, the assisted suicide facility. Lou's mom is furious about this and tells her to not return home if she decides to go. But that's not going to stop her. She makes it to Dignitas in time and shares a tender moment with Will before he goes through with the procedure.
Before his death, Will writes Lou a letter that specifically requests that it only be opened while Lou is a Paris café. So she goes. The letter says that Will has left Lou a small amount of money so she can go back to school and follow her dreams. It also expresses Will's sadness at causing her pain, though he hopes that she will emerge from the other end of her grief as a better person. Thus begins a bold new chapter in Lou's life.
…While everyone else is reaching for the tissue box. (Go on, we won't judge.)