Following the decision to create single-player downloadable content for the game, the development team immediately decided that the story would focus on the character of Ellie; they found that players of The Last of Us were interested to learn about events in Ellie's life prior to the events of the main game, particularly the events involving Riley Abel, whom Ellie mentioned in The Last of Us.
Menyusul keputusan untuk membuat single-player download konten untuk permainan, tim pengembangan segera memutuskan bahwa cerita akan fokus pada karakter Ellie; mereka menemukan bahwa pemain dari The Last of Us tertarik untuk belajar tentang peristiwa dalam kehidupan Ellie sebelum peristiwa permainan utama, terutama peristiwa yang melibatkan Riley Abel, siapa Ellie disebutkan dalam The Last of Us.