Log Horizon, Vol. 10 (light novel): Homesteading the Noosphere: Log Horizon, cartea 10

Almost a full year has passed since Shiroe and the others found themselves stuck in Elder Tales. Most of the Akiba residents have grown accustomed to the new world--though, they still don't want to be there. Minori delivers Shiroe a letter from Roe2, his sub-character from the test server. He suspects she's someone who might be able to explain exactly why the Catastrophe happened and for what purpose.