An enslaved boy around 10 or 11 years old living on a Barbados sugar cane plantation. Assigned to work the fields from a very young age, he experiences a brutal environment before being chosen as a personal assistant to a visiting scientist. He exhibits high intelligence, a natural affinity for drawing, and an intense scientific curiosity despite his traumatic early life.

The younger brother of the plantation owner, dedicated to scientific research and the pursuit of a hot-air balloon project called the Cloud-cutter. He selects an enslaved boy as his assistant to help draft diagrams and conduct experiments. While he finds the institution of slavery distasteful, he relies entirely on enslaved labor to advance his personal projects.

A physically imposing field slave on Faith Plantation originally from the African kingdom of Dahomey. She steps in to care for an orphaned boy, serving as his primary protector against the violence of both overseers and fellow workers. She holds deeply rooted religious beliefs about the afterlife, maintaining that death acts as a door back to her homeland.

The new owner of Faith Plantation, having inherited the sugar cane estate from his uncle. He manages the property with an emphasis on strict profitability, replacing the previous overseers with men who utilize torture and extreme abuse. He views the enslaved workforce entirely as property and refuses to tolerate insubordination.

An accountant who transitions into a career as a bounty hunter operating in the West Indies. He enforces a rigid worldview that demands strict racial hierarchies, applying his education and intelligence toward tracking down escapees. He operates with a cold, relentless efficiency across multiple continents.

A spirited young woman of biracial heritage whose mother was from the Solomon Islands. She receives a formal education from her father and develops a deep passion for marine biology and illustration. She manages the strict social expectations placed upon her while pursuing an independent intellectual life.

A cousin to the plantation owners who travels from England for an extended visit. He is an anxious, gluttonous man who spends his days eating large meals and avoiding responsibility. He carries long-standing psychological wounds from a childhood marked by severe bullying from his relatives.

A dedicated scientist conducting specialized research in a freezing, remote environment. He is emotionally closed off from his family, preferring the isolation of his extreme working conditions over social or domestic obligations. He holds strict, outmoded prejudices that color his interactions with those outside his immediate circle.

An esteemed author and marine scientist who carefully studies aquatic life. He takes a highly protective stance over his daughter, guarding her against societal prejudice while maintaining his own strict standards for proper associations. He possesses a keen eye for scientific accuracy and illustration.

A dedicated assistant who supports a prominent scientist in harsh, isolated research camps. He handles the day-to-day survival of the encampment and serves as a steady, quiet companion to his employer, offering practical support and resources when needed.

A ship captain of German and English descent who commands a vessel crewed by orphans. He is a practical and observant leader who handles unexpected situations with efficiency, carrying a quiet sorrow while maintaining authority over his ship.

An identical twin who serves as a ship's surgeon. He possesses sharp deductive skills, quickly assessing the true circumstances of his patients without pressing them for dangerous details, and provides vital medical care in high-pressure situations.

The caretaker of a lodging house in a cold coastal town. As a Black man operating within a highly prejudiced environment, he offers practical advice and blunt warnings to newcomers. He is physically tough and willing to violently defend his friends when provoked.

A parish sexton in Virginia with a morbid fascination for anatomy and decomposing bodies. He holds strange philosophical views regarding the vulnerability of childhood and provides covert assistance to those traveling through the region.