Keeper of the Lost Cities contains aspects of several major literary forms: fantasy, coming-of-age, hero’s journey, and adventure. These combine to form a story tuned to the interests of middle-grade readers.

Fantasies contain elements that are fantastic or magical, things not possible in the real world. In high, or full, fantasy, a fictional world is imbued, through and through, with magical elements. Examples include epics such as the Lord of the Rings series and TV’s Game of Thrones. In low, or partial, fantasy, miraculous powers intrude on an otherwise normal world. The book Half Magic, about a coin that grants wishes by halves, and the Kingdom Keepers series, in which a group of kids nightly enter a magical realm inside Disney World, are types of low fantasy.

Keeper of the Lost Cities introduces readers to a hidden realm on Earth controlled by elves, a species of highly intelligent human-like beings, many of whom have magical abilities: telepathy, psychokinesis, pyrokinesis, mesmerism, and others. Much of the story concerns their use of these powers while dealing with a crisis in the human world. Thus, Keeper of the Lost Cities is a form of low fantasy: Its magical elf realm intrudes on the normal, everyday reality of Earth.