Jane is the eldest of the four siblings. As the emotional leader of the group, she naturally assumes authority and creates rules to organize their magical activities. She possesses a fiery temper but feels fiercely protective of her younger siblings. Because she remembers her late father best, she struggles with the idea of anyone replacing him in their household.

The second oldest child and the only boy in the family. Mark prides himself on his logical thinking. He frequently steps in to calm his sisters when situations escalate and prefers talking through problems over acting on emotion. Missing a male presence in his life, he quickly admires adults who treat him with respect.

Katharine is the middle daughter of the family. She reads voraciously and enjoys imagining romantic, grand scenarios. While typically docile and eager to please, she desires recognition for her good deeds. If adults ignore or dismiss her contributions, she reacts with surprising aggression.

The youngest of the siblings, Martha demonstrates typical childhood stubbornness. She acts on her immediate feelings, often throwing tantrums or making hasty demands without thinking ahead. Despite her occasional selfishness, she looks up to her older brother for guidance.

The children's widowed mother works as a journalist covering women's society events. She maintains a practical, no-nonsense approach to life and refuses to believe in the supernatural. When faced with inexplicable events, she assumes she must be suffering from a medical issue rather than accepting magical explanations.

Mr. Smith runs a local bookstore and possesses a gentle, welcoming demeanor. He stands out from other adults because he genuinely hopes to encounter magic and respects children's imaginations. His willingness to entertain the impossible allows him to bond quickly with the siblings.

Miss Bick looks after the four siblings during the day while their mother works. She runs a tight ship, enforcing strict daily routines and chore schedules. Her authoritative presence represents the mundane reality the children wish to escape.

The family's pet cat. Named after a prominent women's rights activist, she becomes an early test subject for the magical coin. As a result, she temporarily gains the ability to speak, though her dialogue consists entirely of confusing gibberish.

An Arab traveler who crosses paths with the children during an accidental desert excursion. He recognizes their coin as a valuable artifact from his culture and demands its return. Though initially perceived as a threat, his difficult life circumstances ultimately earn the children's sympathy.

A famous knight of Arthurian legend. He projects confidence and superiority, eagerly rushing into danger to save distressed gentlewomen. However, he exhibits significant arrogance and fails to show appropriate gratitude when others come to his rescue.

An enchantress who plots against King Arthur's court. She uses disguises and deception to lure famous knights into ambushes. Her ultimate goal involves capturing the Knights of the Round Table to dismantle the current reign.

The legendary wizard of Camelot. He possesses genuine magical abilities and understands the severe consequences of altering history. He firmly steps in to correct the timeline after the children interfere with established legendary events.

A severe, humorless woman who values cleanliness and order over joy. She forbids toys and muddy activities in her house. When she discovers a strange artifact in her home, she immediately confiscates it.

The legendary British monarch who rules over Camelot. He oversees the knightly competitions and relies on his wizard's counsel when strange events disrupt the proceedings.