From the introduction: From another point of view this is Theldesia, a world that survived one apocalypse only to be faced by another when the Alv Princesses caused the World Fraction to avenge their race, summoning unending waves of demi-human monsters. A second World Fraction brought the inhuman but powerful Adventurers to their world - legendary but unsettling beings prone to getting hung up on terrain any fool could navigate and awkward to talk to but willing and able to battle monsters for gold and other rewards. Now another World Fraction has Adventurers acting as if they're people all of a sudden. Welcome, dear Jumper, to Log Horizon. You start the day of the catastrophe, along with you there are several confused and powerful beings.