Ellie Williams[7] is the central character of The Last of Us series.[fn 1] She serves as the protagonist of The Last of Us: American Dreams, the playable deuteragonist of The Last of Us, the playable protagonist of The Last of Us: Left Behind, the playable dual protagonist of The Last of Us Part II,[1][8] and a playable character in the No Return mode.[9] Ellie grew up as an orphan in the Boston quarantine zone and attended a military preparatory school, where she met and befriended Riley Abel. When Ellie was fourteen, the pair were both infected with the Cordyceps brain infection, where Ellie discovered she was immune. A friend of her mother's and the leader of the Fireflies, Marlene, believed that she was the key to reverse engineering a vaccine. Marlene tasked Joel Miller, a smuggler, with escorting Ellie outside of the QZ. The simple drop-off turned into a year-long journey across America, and the two eventually formed a close bond. Upon reaching the Fireflies in Salt Lake City, Joel learned that only killing Ellie could create the cure. Refusing to allow this, he killed the head surgeon and escaped with Ellie to settle down in Jackson, his brother's community in Wyoming. For the next four years, Ellie came to resent Joel for saving her life. In 2038, Abby Anderson, a former Firefly and the surgeon's daughter, found and killed Joel. Ellie vowed revenge and pursued Abby to Seattle. Her efforts were fruitless, leading her to retire on a farm with her girlfriend Dina and her son JJ. Unable to forgive Abby, Ellie abandoned her family and pursued her once again to Santa Barbara, only to spare Abby in the end. She returned to Jackson once more, coming to terms with Joel's death and his decision to save her life.