The fantasy realm of Rukiya's favorite book, recreated aboard the Enterprise by a nebula entity and later found as a flat world in space.
The Elysian Kingdom is the setting of The Kingdom of Elysian, a fantasy book by Benny Russell that is a favorite of Rukiya, Joseph M'Benga's daughter. In The Elysian Kingdom, a conscious nebula detects Rukiya's loneliness and transforms the Enterprise's interior into the kingdom, with the crew unwittingly acting out its characters.
The nebula also cures Rukiya's disease, and she chooses to live on within it as an energy being, a decision M'Benga reluctantly accepts.
In Once La'An a Time, the Enterprise encounters a mysterious flat world traveling through space, which turns out to be the Elysian Kingdom, created by Rukiya and populated by fantasy versions of the crew. After the defeat of Queen Neve, Pelia stays with the habitat to bring it to port.