Liz is a 19-year-old escaped slave who experiences intense, confusing visions of the future following a severe head injury. Raised on the Spocott plantation, she flees sexual abuse from her owner and survives an attempted capture. Her prophetic dreams earn her the reputation of a 'two-headed' woman, making her both a target for bounty hunters and a figure of mystic significance among other enslaved people.

Denwood is a former slave catcher known as 'the Gimp' who currently works as an oysterman on the eastern shore of Maryland. He carries heavy psychological scars from his past profession and a personal tragedy involving his infant son. Despite his fearsome reputation, he is a complex man struggling with inner rage and an urge to find peace.

Amber is an enslaved man belonging to Kathleen Sullivan who has spent years delaying his escape plans to protect his relatives. He is deliberate, cautious, and intensely loyal to his family unit. His encounter with the mysterious Dreamer upends his careful plans and challenges his belief that physical freedom alone brings happiness.

The Woolman is a legendary, quasi-mythical figure who escaped into the swamps as a young child. He lives entirely outside society, blending into the forest so completely that many consider him a mere rumor. He views the land as a living entity and exists in total harmony with the natural elements.

Patty is a notorious and ruthless 'trader of souls' who kidnaps and sells escaped slaves and freemen alike. She is beautiful, fiercely strong, and driven entirely by materialism and pride. Her humiliation at losing several captives fuels a relentless, vengeful pursuit across Dorchester County.

Kathleen is a farm owner living on Blackwater Creek who struggles to maintain her property and raise her three sons alone. She considers her enslaved workers to be like family, a belief that masks the harsh realities of ownership. Her husband's absence forces her to confront her changing views on the institution of slavery.

Joe is Patty Cannon's weak-willed son-in-law and accomplice. He owns a tavern that secretly serves as a holding cell for kidnapped individuals. Though he possesses vague desires to be a decent person, his greed and subservience to Patty override his moral compass.

The Blacksmith is a highly influential freedman whose genteel appearance belies his dangerous secret work. He refuses to use a given name, viewing anything provided by white society as dishonest. Operating from his shop, he is a primary conductor on the underground network, using his anvil to broadcast hidden messages.

Clarence is a store assistant who deliberately acts slow and stooped to remain invisible to white residents. In reality, he is a sharp, fiercely dedicated operator in the underground freedom network. He views his work as a holy duty and strictly adheres to the secret code.

Wiley is the teenage son of Mary and nephew of Amber, enslaved on the Sullivan farm. He is eager for freedom but terrified of the consequences. His involvement with Liz and the subsequent chaos make him fear that he will be the scapegoat for any disasters that befall his white owners.

The Woman with No Name is an elderly captive who recognizes Liz's prophetic abilities. She acts as a mentor, teaching Liz the fragmented, cryptic rules of the underground communication network. Though physically frail, she possesses immense spiritual authority among the prisoners.

Mary is Amber's sister and Wiley's mother, enslaved by Kathleen Sullivan. She is highly perceptive and secretly knowledgeable about the underground communication codes. She orchestrates messages to protect her family while managing her duties on the farm.

Stanton is a white crew member working for Patty Cannon and Joe Johnson. He is suspicious of his employers and wary of the dangerous situations they force him into, particularly their encounters with the infamous Gimp and the mysterious Woolman.

Big Linus is a gigantic, physically imposing enslaved man held captive by Patty Cannon. His enormous size terrifies others, but he relies heavily on the guidance of the Woman with No Name to remember the complex escape codes.

Jeff Boy is Kathleen Sullivan's eldest son. He enjoys a close, affectionate bond with Amber, often working alongside him. His innocence places him at the center of a brutal conflict when he becomes a pawn in a larger struggle.

Herbie is the negligent deputy constable in Cambridge City. He views his duties, particularly those involving enslaved people, as irritating interruptions to his gambling and personal comfort.

Captain Spocott is a wealthy, arrogant plantation owner and mill operator. He is Liz's legal owner, desperate to recapture her to hide his history of abusing her.

Little George is an enslaved teenager working for Patty Cannon. He enjoys a favored position that allows him to prey on female captives held in the attic, until the prisoners violently turn against him.

Franz is a Bavarian immigrant and Jewish store owner in Cambridge City. He tries to remain neutral in the racial conflicts of the eastern shore but struggles to suppress his innate empathy for those suffering.

Uncle Hewitt is an older enslaved man on the Spocott plantation who raised Liz after her parents were lost. He taught her to leave her anger in the hands of God.

Eb is a young enslaved boy kept in Patty Cannon's service. He runs errands and acts as a lookout for Patty and Joe, enduring the dangerous whims of his captors.

Ducky is a local fixture in Cambridge City who feigns mental incompetence, quacking and jumping for coins. In reality, he uses this harmless persona to spy on white residents and pass warnings to the underground network.

The Woolman's Son is a wild, nonverbal seven-year-old boy living secretly in the swamp. His severe leg injury forces his father out of hiding to seek medical help, triggering a chain of violent events.

Tolley is a representative of Captain Spocott tasked with hiring the best tracker available. He fears the rumors of Liz's supernatural abilities and quickly leaves after passing on the assignment.

Louie is an enslaved man living in an isolated cabin. He deeply fears the swamp legends and the danger of assisting runaways, choosing to stay out of the underground network's operations.

Sarah is Louie's wife. She secretly aids the underground network by leaving food and tying coded knots in ropes to guide runaways safely past their property.

Boyd is Kathleen Sullivan's husband who vanished six months earlier while oystering. His long absence forces his wife and enslaved workers to adapt to a new, precarious reality on the farm.

Lums is an enslaved man on the Spocott plantation. He skillfully uses neutral expressions and vague answers to hide information from white interrogators while communicating history about Liz's past.