In the video game and TV show "The Last of Us", Joel lives in a post-apocalyptic world where a zombie virus has taken over the earth for the last 20 years. He comes across a 14-year-old girl named Ellie, the first human that is discovered to be immune to the virus. Joel is tasked to take Ellie to a hospital, in a journey taking approximately 1 year, in the hopes that a cure to the virus could be developed.
Right at the end of the journey, they are both knocked unconscious and taken to the hospital where it is discovered that Ellie has to die in order for the vaccine to be developed. Joel then is faced with a choice, to save Ellie and escape, leaving behind humanity's only hope to develop a cure; or to let Ellie, whom he has developed a father-daughter bond with after losing his own daughter 20 years ago, die in order to save humanity.