The Twilight Brigade continues it's search for the Virus Cores, a mysterious item not included in the official game specs. They believe they need to collect them before they can find out the coveted Key of the Twilight. Meanwhile their rival Guild, TaN, bears down on them harder using their secret service led by a dangerous Player Killer Ender. Haseo comes up with a clue on how to use the Virus Cores in one of the Lost Grounds. As their leader Ovan decides to take action, even Gord and Bset, who left the guild in disappointment, join them again and fight against the enemy warriors. Little do they know, however, that Naobi, the TaN's mastermind, is intriguing to set them up in a trap so that he can achieve his own sinister goal.