World Fraction (Episode)

World Fraction (ワールドフラクション) is the fourteenth episode of the Log Horizon anime. It aired on January 4th, 2014.

Synopsis
Shiroe and Akatsuki follow ReGan to his library, where he had shelves filled with books and scrolls.

Being an academic in the study of World-class magic, ReGan offers Shiroe and Akatsuki an explanation of the World Fraction spell and the three times it has been used in the world's history, with Shiroe correctly deducing the third time being the Catastrophe. ReGan explains that 350 years ago, the Human, Elf, and Dwarf races destroyed the Alv kingdom out of jealousy of the Alvs' advanced magical technologies. Seeking revenge, the Ruquinjé were the masterminds behind the long terrible war between humans, dwarves, and elves to avenge their people's destruction. However, at their defeat, they cast the first World Fraction, which resulted in the creation of the endlessly-respawning demi-human monsters, which pushed the planet into a world war. This caused humanity to create powerful hybrid races to aid in the war, until around 240 years ago, they were forced to cast the second World Fraction to summon the Adventurers to their aid.

ReGan also explains that Shiroe's name appeared in the world's history some 98 years ago, and Shiroe confirms that the events using the game's rate of time correlates to the real world by a factor of 12, including the start of the open beta which brought the human-controlled Adventurers and when he began playing Elder Tale. ReGan then moves on to explain his Spirit Theory which involves how revival works and that memories in the form of XP are lost during the process—a theory which Shiroe decides to withhold from the Round Table Alliance for the time being. Meanwhile, Minori finally decides to speak her mind to the training group.

Trivia

 * In the Japanese boxed DVD set, the episode guide called this episode "Universal Turbulence," even though the episode's title is spelled out in English with katakana.