Operation Capture, also known as Operation Retake and the Akiba Raid, was an event in the first December after the Catastrophe when a rogue Royal Guard began murdering Adventurers in the city of Akihabara.
After acquiring the sword Byakumaru from Tatara's shop, the Royal Guard Enbart Nelles stole one of the Kunie's Mobile Armor. He started going on a player-killing rampage within the city of Akihabara using the sewers as a place to conceal himself.
This happened due the flavor text of items starting to come into effect, and he was no longer operating under his own free will, instead being possessed by the vengeful spirit of the raid boss Lugrius which was inside the sword.
In order to put an end to the threat, the Akiba Raid Party was formed to fight this Guard with Raid Boss capabilities. A curfew was established so that the only players Nelles could target were the members of the raid party, and the raid party was split into several small teams so that they could minimize the effect of Lugrius' raid boss abilities (which multiplied his power based on the number of people within a 50-meter range).
The raid party was successful and Enbart Nelles was successfully captured.
However, in the process of capturing Nelles, the raid party was forced to turn off the magic circle in Akiba, which allowed the Mobile Armor to function and kept monsters out of the city. Even though monsters could be kept at bay by Adventurer patrols, this also meant that fighting was now allowed in the city and would have to be regulated by the Adventurers themselves.
- ↑ Log Horizon light novel: Volume 6