The largest part of the book, "The Story of the Vivian Girls, in What is Known as the Realms of the Unreal, of the Glandeco-Angelinian War Storm Caused by the Child Slave Rebellion", follows the adventures of the daughters of Robert Vivian, seven princesses of the Christian nation of Abbieannia who assist a daring rebellion against the child slavery imposed by John Manley and the Glandelinians. Children take up arms in their own defense and are often slain in battle or viciously tortured by the Glandelinian overlords. The elaborate mythology includes the setting of a large planet, around which Earth orbits as a moon (where most people are Christian and mostly Catholic), and a species called the "Blengigomeneans" (or Blengins for short), gigantic winged beings with curved horns who occasionally take human or part-human form, even disguising themselves as children. They are usually benevolent, but some Blengins are extremely suspicious of all humans, due to Glandelinian atrocities.