Cassia Maria Reyes
The story’s main protagonist and narrator, Cassia is seventeen years old, with green eyes and “coppery" brown hair. She is a student at Second School, but also works as a data sorter. She is very physically active, often running on her tracker, and choosing hiking as a summer leisure activity. Cassia begins the story as a comfortable, happy pawn in the Society’s totalitarian game. As she slowly becomes both self-aware and aware of the Society’s fallibility, she begins to question the status quo. Over the course of the book, she becomes completely disillusioned to the Society's lies; ultimately, she is willing to betray her Match with Xander for the chance at liberation and happiness with Ky.
Xander Carrow
Cassia’s lifelong best friend, Xander is also seventeen years old, with blonde hair and blue eyes. Cassia describes him as very handsome. Xander is compassionate and intelligent; while he generally follows the Society’s rules like everyone else, he isn’t afraid to bend them on occasion. Though Xander is a source of comfort and safety for Cassia, Ky ultimately eclipses his romantic place in her life. Xander is angry and hurt when he learns of their courtship, but ultimately chooses to help Cassia find Ky when he is taken, even risking punishment by swiping extra blue tablets for her. His loyalty and kindness are his defining qualities.
Ky Markham
Ky is another childhood friend of Cassia’s and the boy with whom she eventually falls in love. An Aberration whose father committed an Infraction before both of his parents died, Ky was adopted by his aunt and uncle and brought to live in Oria Province around age ten. He has dark hair and eyes that seem to change with his surroundings -- though he maintains that they’re dark blue. Though Aberrations are not allowed to possess artifacts, Ky owns a compass, which he ultimately gives to Cassia. He can write, a rare ability, and teaches Cassia to write as well so that she can mold an original voice and creativity. Though Ky is very intelligent, he is also reserved, choosing to learn by observation rather than inquiry. He maintains a consistent invisibleness, never drawing attention to himself, especially when it comes to performing well at the game center, or at work. He has a dark, troubling past, which he reveals to Cassia over the course of the story through drawings and writings on napkins.
Molly Reyes, Cassia's Mother
An Arboretum worker, Cassia’s mother takes pride in her family and her job. She loves her husband and family unconditionally and harbors her own defiant thoughts about the Society -- though she rarely expresses these thoughts, for fear of putting herself and her family in jeopardy. She has an affinity for plants, particularly for things that go wildly and without regulation.
Abran Reyes, Cassia’s Father
Cassia’s father is a low level Official in charge of restoring old neighborhoods for use by the public. Though generally compliant with Society regulations, he demonstrates the priority of his love for his family by destroying his dead father’s tissue preservation sample at his father’s request. He is unafraid to defend his daughter’s actions and demand answers when Ky Markham is taken away by Officials, which makes his wife proud.
Bram Reyes, Cassia’s Younger Brother
Bram is unorganized, often getting citations for being late for school or running in public. Though he typically complies with the Society's rules, he demonstrates a moment of defiance when the Officials take his artifact, his grandfather’s old watch: he tells them that it will always belong to him.
Samuel Reyes, Cassia’s Grandfather
A rebel by nature, Cassia’s grandfather Samuel plants the seeds for Cassia’s sense of rebellion and her thirst for knowledge and freedom. A product of a different generation, he and his wife were Matched at the late age of 35, and had their only son, Abran, when they were 39. Samuel was a data sorter like Cassia, and like his son, worked as an Official for many years before retiring at age 70. He is poisoned and killed by the Society on his 80th birthday, as part of a customary Final Banquet.
Cassia’s Official
An Official with particular interest in Cassia, the Official is present throughout Cassia’s relationship with Ky. In the beginning, she is reassuring and comforting, telling Cassia, that despite the malfunction with her microcard, she is still Matched to Xander. Once Cassia’s feelings for Ky become apparent, she becomes threatening and foreboding. By the book’s end, once Ky is taken away, she is downright apathetic and malicious. She personifies the misleadingly kind manner with which the Society treats its citizens while simultaneously dehumanizing them; Cassia’s opinion of the Official over the course the book reflects her opinion of the Society.
Em
Em is Cassia’s oldest female friend. She gets nervous easily and takes her green tablets often.
Norah
Cassia’s supervisor at work. She is unfriendly and somewhat jealous of Cassia’s excellent data sorting performance record.