Jude is a 17-year-old human girl living in the magical, immortal world of Faerie. Taken from her home after the murder of her parents, she strives to find a place in the High King's court despite the constant disdain from the immortal residents. She trains relentlessly in military strategy and sword fighting, hoping to earn a knighthood to secure permanent protection for herself and her family.

Cardan is the youngest son of Faerie’s High King and a privileged prince of the royal court. He is openly hostile toward the mortal sisters at his school, using his elite status to bully those he considers beneath him. Operating with a tight circle of friends, he covers a deep internal vulnerability with arrogance and spiteful behavior.

Taryn is Jude's identical twin sister, also a mortal trying to survive in the dangerous courts of Faerie. Unlike her sister, Taryn takes a conciliatory approach to her environment, hoping to blend in and find a faerie to marry as her path into the High Court. She tries to keep her head down and avoid drawing the wrath of their immortal peers.

Madoc is a powerful redcap general in the High King's army. He is responsible for bringing Jude, Taryn, and Vivi to Faerie after dispatching the twins' parents. Despite this brutal history, he provides his wards with a life of comfort and raises them according to his own strict code of honor, actively teaching Jude the arts of combat.

Vivi is the older half-sister of Jude and Taryn, and the biological daughter of Madoc. Although she possesses magic and immortal heritage, she deeply resents Faerie and her father, preferring to spend her time hoarding mortal objects and visiting the human world to see her girlfriend.

Locke is a faerie youth who runs in the same elite circles as Cardan. However, he distinguishes himself from his peers by occasionally showing kindness and paying special attention to Jude. He lives in an estate with a complex hedge maze and carries a playful, trickster-like demeanor.

Dain is the third child of the High King and the widely anticipated heir to the throne of Elfhame. Recognizing the strategic value in mortals who can lie, he recruits Jude to serve his interests leading up to the coronation, granting her immunity to enchantments in exchange for her espionage.

Balekin is the High King's eldest son and the master of Hollow Hall. He harbors intense ambitions for the throne and maintains a heavily guarded estate. He exerts a harsh, demanding authority over his household, physically abusing his younger brother Cardan.

Oriana is Madoc's second wife and the mother figure to young Oak. A former consort, she maintains a careful, guarded presence in the household. She frequently warns the mortal twins about the dangers of Faerie customs, seeking to maintain order and protect her young son from the volatile politics of the court.

Oak is the young son of Madoc and Oriana. Growing up in a military household, he is playful but possesses natural faerie magic that he occasionally uses without fully understanding the impact it has on his mortal stepsisters.

King Eldred is the current High King of Faerie. He sets the central political conflict in motion by announcing his intention to step down from the throne and select a successor from among his children.

Valerian is a cruel faerie who belongs to Cardan's elite social circle. He takes particular pleasure in bullying mortals and frequently attempts to use magic to physically harm or humiliate Jude during their interactions.

The Roach is a goblin and an experienced spy working in the Court of Shadows. He assists in training Jude in the arts of stealth, subterfuge, and survival, treating her with a mix of skepticism and practical guidance.

The Ghost is a highly skilled faerie operative working for Prince Dain. He acts as a mentor and field partner to Jude in her clandestine assignments, possessing exceptional skills in archery and infiltration.

The Bomb is a female faerie and explosives expert who makes up the third operative in Dain's elite spy network. She helps prepare Jude for the physical and tactical demands of espionage.

Heather is a human girl living in the mortal world who is dating Vivi. She remains entirely unaware of the magical reality of Elfhame or Vivi's true immortal nature, believing her girlfriend's family simply has strict, conservative rules.