A Topside-dwelling protagonist who moves to New York City and finds her life changed by meeting Talon, with whom she explores cultural differences.

Talon’s long-time friend and occasional antagonist, who values Downside rules and represents a foil to Talon’s rebellious nature.

A sidekick who is part of Talon and Railborn’s group, often taking on a supportive yet passive role in their adventures.

A historical figure woven into the narrative as a quirky inventor, fictionalized as the originator of the Downside society.

An enigmatic figure residing Topside, offering guidance and support to both Talon and Lindsay without aligning with either society.

Lindsay’s father, busy with his work on an aqueduct project, who has little meaningful interaction with his daughter.

Lindsay’s chatty sidekick who provides comic relief and aids in research tasks, though she is not a close friend.

Lindsay’s antagonistic stepbrother, known for his troublesome behavior and conflicts with Lindsay.

A young man from the Topside who attempts to transition into the Downside, highlighting themes of societal contrasts.