Half a year has passed since the battle atop the Central Cathedral of the Church of Axioms. Half a year in the virtual Subworld—yet only 4 hours in the real world, where the crew of the research vessel “Oceanic Tortoise” has been subjected to an unexpected attack. A new, powerful enemy is now delving into the virtual space. And the final phase of the experiment with load is only moments away. The fight for Kirito’s life—and for the fate of the entire Subworld—is nearing its climax.