Six months have passed since the fierce battle against Administrator. Alice has brought Kirito to her childhood home, Rulid Village, where they live peacefully. Gazing out at the world that she saved with Kirito, Alice reflects on all that’s happened.

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!

The mysterious group that attacked the Ocean Turtle turns out to be a secret unit under orders from the U.S. National Security Agency. And its leader, Gabriel, has battled Kirito and Sinon before.

Shasta, commander of the Dark Territory's dark knights, had intended to use Administrator's death as a chance for peace with the Human Empire. But his plans are thwarted by Emperor Vecta's return to the land of darkness.

Resolved to fight for humankind, Alice joins the forces of the Human Empire, bringing Kirito with her. But while the forces of darkness boast overwhelming numbers, only thirteen Integrity Knights are available to fight for the Human Empire.

The Final Load Test has begun, and the Eastern Gate has collapsed. Incited by Gabriel, now Emperor Vecta, the massive army of the land of darkness pushes on towards the Human Empire.

Integrity Knight Renly Synthesis Twenty-Seven, in battle for the first time, flees his position, allowing goblins from the forces of darkness to infiltrate to the tent where Kirito is.

The powerful formal art unleashed by the Integrity Knight Alice inflicts severe casualties on the forces of darkness. Alice encounters an enemy survivor and learns that Emperor Vecta's objective is to find the "Priestess of Light."

Upon seeing Alice, Gabriel orders his entire army to capture her. The pugilists guild races ahead of the main force. As Alice and Bercouli try to come up with a strategy to counter them, the silent Integrity Knight Sheyta Synthesis Twelve steps forward.

Asuna has logged into the Underworld using the superuser account of Stacia, the Goddess of Creation. After she descends, she is reunited with Kirito, thanks to Ronie and Tiese. But soon Alice arrives, leading to a precarious situation!

Asuna has created a bottomless chasm. The dark knights and the pugilists attempt to cross over to the other side, where the Human Empire Army waits. Meanwhile, Critter releases an announcement about a limited-time beta test for a bizarre new VRMMO.

Due to Gabriel's scheme, U.S. players were given black knight accounts, and are now continuously logging in to the Underworld. They begin mercilessly slaughtering soldiers from both the Human Empire Army and the Dark Territory Army.

This episode is a recap of Sword Art Online: Alicization - War of Underworld.