Miryem is a young Jewish woman living in a nameless Lithvas town. Seeing her family plunge into poverty due to her father's soft-heartedness, she takes over the moneylending business with iron determination. Her pragmatic, unsentimental approach brings her family financial stability but earns her a reputation for having a heart of ice. When she boasts that she can turn silver into gold, she inadvertently attracts the attention of the perilous Staryk.

Wanda is a tall, blonde farm girl trapped in a harsh life under the thumb of her alcoholic father, Gorek. Fearing he will sell her into a miserable marriage, she eagerly accepts work as a servant and debt collector for the Mandelstam family. The employment provides her with regular meals, a respite from her father's violence, and a chance to learn reading and mathematics.

Irina is the plain-featured daughter of the Duke of Vysnia. Possessing a small amount of Staryk ancestry, she lacks obvious magical abilities but immediately feels a connection to a necklace made of Staryk silver. Her father views her as a political pawn, intending to use the enchanted jewelry to secure a royal marriage, leaving Irina to rely on her quiet observation and sharp wits for survival.

The Staryk King is the ruthless, unearthly ruler of an ice-dwelling fairy race. He controls a moving road, commands freezing winter weather, and fiercely protects all white animals in the forest. Operating strictly on magical bargains and pride, he tests Miryem's boasting by demanding she transmute his silver into gold under threat of being turned into ice.

Chernobog is a malevolent fire demon bound to the royal bloodline of Lithvas. He possesses Tsar Mirnatius, using the human monarch as a vessel to consume power and inflict cruelty. Operating from the shadows, he desires to devour souls and exact total destruction upon the Staryk people and their glass mountain.

Mirnatius is the young, exceedingly handsome, and notoriously cruel Tsar of Lithvas. He delights in tormenting others, an impulse he has displayed since boyhood when he tortured animals for amusement. Behind his sovereign authority lies a dark secret regarding the true source of his power and sadism.

Rakhel is Miryem's gentle and loving mother. She constantly worries about the poverty her husband's soft-heartedness causes, yet she is equally distressed when Miryem adopts a cold, ruthless demeanor to collect debts. She maintains a warm, hospitable home, eventually extending her maternal care to Wanda.

Josef is a moneylender who lacks the necessary cruelty for his profession. Instead of demanding payment from his neighbors, he allows them to defer, plunging his own family into near-starvation. He tries to make up for his professional failures by hunting and foraging, but ultimately must step aside when his daughter takes over the accounts.

Sergey is Wanda's older brother, a growing teenager who takes severe risks to feed himself during the harsh winters. His decision to poach a white rabbit from the Staryk forest nearly costs him his life, permanently shifting the dynamic between him and his sister.

Stepon is Wanda's youngest brother. Small and vulnerable, he depends heavily on Sergey and Wanda for survival in their impoverished, violent household. He maintains a childlike faith in the spirit of their dead mother, who he believes watches over them from the white tree in their yard.

Gorek is Wanda's father, a bitter, alcoholic farmer who uses violence to control his children. He views Wanda purely as an asset to be worked or sold off into marriage to settle his debts and supply him with liquor.

Magreta is Irina's loyal governess and sole confidante. While she recognizes the extreme danger posed by Tsar Mirnatius and his cruel reputation, she lacks the social power to protect her ward from the duke's marital plotting.

The Duke of Vysnia is Irina's father, a wealthy and ambitious nobleman. He values his daughter only as a tool for political advancement, eagerly purchasing enchanted silver to artificially enhance her appeal to the sadistic tsar.

An affluent and highly successful moneylender operating in the city of Vysnia. He provides Miryem with capital to expand her business and validates her cold, pragmatic approach to the trade, arguing that gold has no memory of how it was earned.

Isaac is a skilled jeweler in Vysnia engaged to Miryem's cousin Basia. He partners with Miryem to turn the otherworldly Staryk coins into fine jewelry, entirely mesmerized by the magical properties of the fairy metal.

Oleg is a local sledge driver who owes a debt to Miryem's family. He transports her between her village and the city of Vysnia, but the temptation of the Staryk gold in her possession pushes him toward a desperate and violent betrayal.

Flek is an inhabitant of the Staryk mountain who is assigned to attend to Miryem. Bound by the strict, transactional rules of fairy culture, she cannot answer Miryem's questions without a formal bargain, leading to immediate misunderstandings between the human and her servants.

Shofer is another of the Staryk servants assigned to Miryem. He operates the fairy sleighs along the magical road and adheres strictly to the rigid cultural norms of the ice fairies regarding gifts and debts.

Tsop completes the trio of Staryk servants tending to Miryem. Like the others, Tsop silently performs duties while navigating the dangerous cultural gap between human expectations of kindness and Staryk laws of absolute repayment.