According to Queen, the Cyber World was only created when the Knight created the Dark Fountain within the library, the same day that Kris and Susie visited it. However, the Darkners within it have memories of the world before this point in time, including remembering Lightners' interactions with their Hometown counterparts. Additionally, King and Queen both seem to already know each other, despite King being imprisoned in Castle Town for the entire duration of Cyber World's existence.
Kris and Susie go to the library to work on their group project. However, when they open the door to the computer lab, they discover that the room is now a Dark World. Excited to explore a new Dark World, Kris and Susie jump into it. Inside, they discover that Berdly and Noelle, who had been studying in the computer lab, have also been sucked into this Dark World.
Shortly after Kris and Susie's arrival, Ralsei appears, somehow having traveled to the new Dark World. The three of them journey through the Cyber World together, and ultimately confront Queen.
The party brings Lancer and Rouxls Kaard (and possibly Starwalker) to Cyber World from the Card Kingdom Dark World. However, because they are not native to this Dark World, the former two turn to stone after some time.
At the top of her Mansion, Queen reveals that she is aware of the creation of the Cyber World by the Knight, but that as a result the Cyber World is trapped within the Library. Since any Lightner with enough determination can create a Dark Fountain, Queen reveals that she plans to use Noelle to create Dark Fountains all across the world in order to free the Cyber World of its bounds.
After the party's Thrash Machine defeats GIGA Queen, Ralsei explains to Queen that her plan would bring about the Roaring, a cataclysmic event brought about when Dark Fountains fill the sky. Queen, unaware of this, gives up on her plan and allows Kris to seal the Cyber World's Dark Fountain.
After Kris seals the Dark Fountain, the four Lightners awake in the Library's computer lab. After everyone else leaves, Kris gathers all the items from the lab, and takes them to the school's supply closet. This allows all the residents of Cyber World to come to Castle Town.
Cyber World is divided into three main subareas, each with their own sublocations.
- (You touched the light...) (You thought about how you can't go back to the Cyber World anymore.) (You considered this carefully!) - Castle Town SAVE point
- The Knight. The Roaring Knight... Today, It Deigned To Create This World. Reaching Its Long Hand To The Sky. It Coursed Its Will Into Its Blade. And Made. Thrusting The Fountain From The Earth. - Queen before the GIGA Queen fight
- The day he was to be evicted from the Queen's mansion, I went to his room to check on him... - Addison in the Trash Zone
- That robot was the embodiment of a Lightner's dream. A dream I helped create... once. Splashing color from the motion of their hand. - Swatch
- For some reason, his products never seemed to hit... ... and the Lightners never even looked his way. - Addison in the Trash Zone
- What purpose have you here... Queenie Beanie - King when being taunted by Queen in the Castle Town prison
- If you didn't know, an evil ruler is taking over this world. I don't really like politics, so I have no opinion on this. - Plugboy with hat in Cyber Field