In the real world, Kazuto Kirigaya lies unconscious. At Kikuoka’s request, Kazuto is moved to a well-equipped hospital, but when Asuna and Suguha try to visit, they’re turned away. Suspicious, Asuna and the others split up to find out more about Rath.

When Kirito and Alice both unleash the Perfect Weapon Control art in the Cloudtop Garden, the impact rips a hole into the seemingly impregnable Central Cathedral wall, which sends them both flying outside.

Carrying the hopes of Cardinal, Eugeo, and Alice in his heart, Kirito stands yet again and visualizes the Black Swordsman, the top player who cleared SAO. For the sake of everyone he’s encountered in this world, Kirito, faces off with Administrator.

Recap of Sword Art Online: Alicization, aired one week before Sword Art Online: Alicization - War of Underworld.

A force from the Dark Territory is attacking Rulid Village. Though she’d lost her purpose in battle, in order to fight for her family, and for the people that Kirito and Eugeo tried to protect, Alice takes up the Osmanthus Blade once again!

Escaping his nightmares, Kirito regains consciousness at last. With the Night-Sky Blade in his right hand and the broken Blue Rose Sword in his left, he faces off against Vassago, armed with the Mate-Chopper, now enormous in size.

The maximum-acceleration phase has begun. Alice successfully logs out of the Underworld, but Kirito doesn’t make it in time. In the real world, Higa and Kikuoka rush to shut down the STL, in order to disable the maximum-acceleration phase, but…