With Sooha now in Dardan's clutches, her life is in grave danger! In order to save her, Heli and his friends investigate a bar called Railgun, where they're ambushed by an enemy vampire with a strange power unlike anything they've encountered. Meanwhile, the werewolves learn that Sooha's kidnapping and the disappearance of their brothers are linked--and all roads lead to the vampire-infested city of Automnal! When friend turns to foe, the boys may have to call upon their past selves to awaken their true power--but will that be enough to rescue Sooha before it's too late?