Harper is a teenager from modern-day Washington, DC, who accidentally gets transported to the magical world of Emberfall after stepping in to save a kidnapped stranger. Living with cerebral palsy, she walks with a limp but refuses to let her physical disability or her family's dire financial struggles define her. She possesses a keen sense of justice, a protective instinct toward the vulnerable, and a stubborn defiance that challenges the royal norms of her new environment.

Rhen is the crown prince of Emberfall, cursed by an enchantress to repeat the autumn of his eighteenth year over three hundred times. At the onset of winter, the curse transforms him into a bloodthirsty monster that ravages his own kingdom. Guilt-ridden over the destruction of his family and subjects, he initially masks his despair with arrogance and royal detachment, but he genuinely desires to save his people from the torment he caused.

Grey is the last surviving member of the royal guard in Emberfall. Bound by a strict oath to obey and protect Prince Rhen, he is tasked with traveling to the modern world each season to kidnap a girl who might break the curse. Despite his grim duties and terrifying reputation, he is patient, observant, and deeply caring toward those under his protection.

Lilith is a powerful, malevolent enchantress who cursed Prince Rhen following his rejection of her advances. Driven by a desire for revenge after Rhen's grandfather banished or killed other magic users, she uses her inhuman beauty to manipulate others and her magic to inflict brutal torture. She dictates the cruel terms of the curse and enjoys watching Rhen suffer over the centuries.

Jake is Harper’s older brother, thrust into the dangerous role of a debt collector to keep their family afloat after their father dies. He acts as the primary provider for their terminally ill mother. Desperate and fiercely protective, he often tries to shield Harper from danger, sometimes underestimating her capabilities due to his constant worry over her physical safety.