During their Sword Art Online Summer Festival event at Anime Expo, Aniplex of America unveiled the first promo video for Sword Art Online: Alicization. This is the third official season of Reki Kawahara’s light novel series and it is scheduled to air in Japan this October. The events of the anime will take place after the main Gun Gale Online arc. The third season was officially announced in October 2017 during the Dengeki Bunko Fall Festival.
MyAnimeList.net describes the story of Sword Art Online: Alicization as follows:
Kirito awakens in a vast, fantastical forest filled with towering trees. In his search for clues to the truth of his surroundings, he encounters a young boy who seems to know him. He ought to be a simple NPC, but the depth of his emotions seem no different than a human. As they search for the boy’s parents, Kirito finds a peculiar memory returning to him. A memory from his own childhood, of this boy and a girl, too, with golden hair, and a name he should have never forgotten—Alice.
The promotional video, complete with English subtitles can be viewed below
In addition to the promotional video, Aniplex of America also unveiled the following key visual for the third season: