Ep. 16: Kirito memasuki Alfheim Online untuk menemukan Asuna di Pohon Dunia dengan bantuan Yui.

Kazuto visits Andrew, who explains that the screenshot he sent originated from "Alfheim Online" (ALO), a VRMMORPG where players take the role of fairies capable of flight. He explains that the figure resembling Asuna was spotted somewhere on the game's World Tree. Discovering that RECTO (the company for which Sugou works) created the game, Kazuto is convinced that Asuna is trapped in the game. Wasting no time, Kazuto logs-in to ALO as "Kirito." He discovers that he still has his SAO game data, including skill levels and the SAO in-game item containing Yui's data, which he activates to bring Yui into ALfheim as a Navigation Pixie. Yui deduces that the game is made using a copy of SAO's servers, explaining why Kirito's statistics, a piece of data from SAO had been carried over to Kirito's ALO avatar. (Source: Wikipedia)
Episode
- Ep. 12 · Kirito dan Asuna menyelamatkan Thinker sementara Yui mengorbankan keberadaannya sebagai AI.
- Ep. 13 · Kirito dan Asuna membantu Nishida memancing sebelum menghadapi raid bos
- Ep. 14 · Akhir Dunia dan Duel Terakhir
- Ep. 15 · Kazuto mengunjungi Asuna yang koma dan menghadapi rencana adopsi Sugou sambil menerima email misterius.
- Ep. 16 · Kirito memasuki Alfheim Online untuk menemukan Asuna di Pohon Dunia dengan bantuan Yui.
- Ep. 17 · Leafa mengajarkan Kirito terbang dan merencanakan pendakian ke puncak World Tree
- Ep. 18 · Leafa memimpin Kirito ke Pohon Dunia setelah meninggalkan partinya untuknya
- Ep. 19 · Kirito dan Leafa menavigasi Koridor Lugru sambil menghindari pengejaran Salamander.
- Ep. 20 · Kirito Mengelabui Jenderal Salamander untuk Melindungi Pertemuan Aliansi Sylph dan Cait Sith