Howell sells Hiram's mother Rose, leaving young Hiram motherless and eventually to be raised by Thena.

Hiram is moved to the big house at Lockless and begins regular tutoring sessions with Mr. Fields.

Howell assigns Hiram to serve as Maynard's full-time personal manservant, ending Hiram's years of formal education.

Hiram visits Georgie Parks in Starfall to ask for help escaping Lockless.

The coach crashes into the Goose River, killing Maynard, and Hiram is mysteriously transported to the Walker monument.

Hiram and Sophia agree to run away together using Parks as their guide out of slave country.

Parks brings Ryland's Hounds to the meeting point and delivers Hiram and Sophia directly into captivity.

Howell authorizes Hiram's sale, and Hiram is blindfolded, transported, and thrown into a dark pit.

Corrine and Hawkins reveal themselves as leaders in the Underground and explain that Corrine purchased Hiram.

Hiram accidentally Conducts himself while eating gingerbread alone by the Philadelphia riverfront.

Bland is killed by authorities during his mission to free Otha's wife and children from slavery in Alabama.

Moses Conducts herself and Hiram across the Delaware River and reveals the full mechanics of how the power works.

Hiram returns to Lockless as his father's head servant, secretly working as a spy for the Underground.

Hiram finds the shell necklace hidden in Howell's desk and recovers his long-blocked memories of his mother.

Hiram Conducts Thena to Philadelphia; Corrine then purchases Lockless and establishes it as an Underground station.

Hiram Walker, the enslaved son of plantation master Howell, grows up at Lockless after his mother Rose is sold away, and his exceptional intelligence earns him a place in the big house as Maynard's manservant. After Maynard dies in a mysterious coach accident, Hiram attempts to escape with Sophia but is betrayed, sold, and thrown into a pit. Rescued by the Underground's Corrine Quinn, Hiram discovers his supernatural power of Conduction and begins training as an agent in Philadelphia. A devastating mission to Alabama ends with Bland's death, but Harriet Tubman teaches Hiram the true mechanics of his power before he returns to Lockless as a covert spy. He ultimately recovers his blocked memories of Rose through a hidden shell necklace, channels that emotional power to free Thena, and watches Corrine transform Lockless itself into an Underground station.

The core arc of Hiram's journey from slave to Underground agent.

Young Hiram rushes to the stables after Rose is sold and sees a blue door open above the water trough.

Howell tosses Hiram a copper coin during a public performance on the Street, marking the boy as exceptional.

Thena warns Hiram that living closely with the masters brings greater danger and less freedom than life on the Street.

The night before the accident, Hiram reads about Oregon and dreams for the first time of running North to escape slavery.

Hiram finds his copper coin near the Walker monument, confirming he was transported there and that Hawkins' account is false.

Sophia dances with water jars at the Christmas celebration, and Hiram realizes he has fallen in love with her.

Sophia tells Hiram about her forced relationship with Nathaniel and her refusal to bring children into slavery.

Thena warns Hiram against pursuing Nathaniel's concubine; Hiram rebukes her with words he will come to regret.

Hiram endures repeated hunts as prey for low whites, growing stronger and more cunning with each brutal pursuit.

Hiram forges documents to frame Georgie Parks as an Underground agent, condemning Parks to death at the Quality's hands.

Otha leads Hiram and an angry crowd of free people to confront a slave catcher and rescue Mary Bronson and her son.

A Ryland's Hound kidnaps Hiram on a Philadelphia street, and Bland kills the captor to free him.

Hiram and Sophia make love, and Hiram understands that genuine emotion—not just memory—is the true fuel for Conduction.

Thena is attacked and robbed of all the money she had been saving to purchase her own freedom.

Corrine purchases Lockless to settle Howell's debts, and Howell dies within the year.

From his first mysterious vision of a blue door at a water trough to his growing love for Sophia, this pool traces the intimate and often painful moments that shaped Hiram's journey. A copper coin from Howell, a Christmas dance, and a series of small betrayals and unheeded warnings build a picture of life at Lockless that the main plot can only sketch. In Philadelphia, Hiram witnesses the brutal realities of fugitive life, from rescuing Mary Bronson to surviving a kidnapping by Ryland's Hounds, while forged documents quietly condemn Georgie Parks. Back at Lockless, love and loss intertwine as Hiram and Sophia draw closer while Thena is robbed of her hard-won savings. The pool closes with the quiet transfer of Lockless itself, a final accounting of everything spent to reach that moment.

The hidden details and personal costs of Hiram's life in slavery and the Underground.

Hiram comes to understand, through years alongside Maynard, that the Quality are weak and dependent while the Tasked possess true genius.

Hiram watches Maynard embarrass himself repeatedly among the Quality and grasps that his own future holds only servitude, not recognition.

Hiram drives Maynard to Starfall for the races and resolves that buying or stealing his freedom is the only escape.

Sophia tells Hiram there is no real freedom for a woman in trading a white man's control for a colored man's.

Ryland's Hounds chain Hiram and Sophia in separate cells; Sophia stretches her chains just far enough to touch Hiram.

Trapped in the pit with nothing else to hold onto, Hiram devotes all his energy to reconstructing his memories of Rose.

Hiram completes his first forgery assignment at Bryceton, crafting a day pass that allows an enslaved man named Levity Williams to escape.

Corrine reveals that Harriet Tubman, known as Moses, is the only other living person known to possess the power of Conduction.

Hiram joins Bland on his first field mission and helps free Parnel Johns, gaining real experience as an Underground agent.

Moses explains to Hiram that Conduction requires water, a known destination, and memories charged with genuine emotional feeling.

Hiram confronts Robert during the escape mission, arguing that no one touched by slavery can claim to be morally pure.

Hiram strikes a deal with Corrine: he will spy at Lockless in exchange for her promise to eventually free Sophia and Thena.

Hiram returns to Lockless and discovers Sophia has a daughter, Caroline, revealing she was already pregnant when they tried to escape.

Sophia reveals that Corrine secretly freed her from Ryland's Jail and asked her to pass information about Lockless in return.

Hawkins urges Hiram to abandon his plans, but Thena finally agrees to leave Lockless and let Hiram Conduct her to freedom.

This pool captures the interior turning points that push Hiram from a dreaming boy into a man of purpose and power. He sees through the myth of the Quality's superiority, resolves to be free at any cost, and hears Sophia articulate the gendered limits of the freedom he imagined for them both. After betrayal and imprisonment, Hiram turns inward in the pit, reconstructing his mother's memory as the only power available to him. His education deepens in the Underground through his first forgery, his first field mission, and Moses' revelation of how Conduction truly operates. The pool ends with the most personal of bargains: the negotiated promises and hard-won consents that allow Hiram to act and, finally, Thena to trust enough to go.

The revelations, decisions, and emotional shifts that forge Hiram's identity and power.