Humphrey is a pub landlord and father who assumes numerous identities within a sprawling, cyclical dream. He stands accused of committing a scandalous act in Phoenix Park, causing him great anxiety. His character functions as a living repository of Irish cultural history, shifting forms and names constantly throughout the night.

Anna is the steadfast wife of Humphrey and mother to his three children. She attempts to protect her husband's reputation from the spreading rumors by dictating a long letter. She identifies closely with the River Liffey, flowing consistently forward and bringing life to the environment around her.

Shaun is the brash and practical twin brother of Shem. He frequently assumes the role of a postman attempting to deliver his mother's letter. He tries to assert physical and rhetorical dominance over his brother to prove he is the rightful heir to his father's position.

Shem is the introspective, artistic twin brother of Shaun. He acts as the transcriber of his mother's letter. He passively observes his brother's aggressive behavior and prefers to focus on his creative, intellectual pursuits.

Isabel is the young daughter of Humphrey and Anna. She acts as a constant audience for her brothers' continuous debates and competitions. She struggles to establish an independent identity while receiving excessive, sometimes inappropriate, attention from her male family members.

Kate is a woman who scrubs dishes at the Dublin pub and hosts tours of the Willingdone Museyroom. She operates on the periphery of the main family's affairs. She frequently delivers messages and directly observes the family's activities during the night.

A panel of four elderly men who repeatedly sit in judgment. They appear in various forms, including historians, pub patrons, bedposts, and authors of the gospels. They observe and severely critique the actions of the main family members.

Hosty is an Irish folk musician. He turns the spreading rumors into a popular song called The Ballad of Persse O'Reilly, cementing the public perception of the events.

A pair of local women washing garments on the riverbank. They yell rumors across the water, piecing together the gossip surrounding the local family until they eventually transform into a stone and a tree.

Tim is a construction worker from an old Irish folk ballad. He suffers a severe fall but revives during his wake when someone accidentally spills whiskey on his body.

Finn is a traditional Irish folk hero and giant who rests dormant beneath the city. His grand mythological history intersects directly with the dreams of the sleeping pub landlord.

Military men who allegedly observe an inappropriate act in the park. They testify in court, though they fail to verify their accounts effectively.

Maidservants walking through the local park. They are the alleged victims of a public exposure incident, though the details of their experience alter with every retelling.

A man living in local lodging houses. He hears and spreads rumors regarding the alleged incident in the park.

A person staying in local lodging houses. She participates actively in spreading the gossip regarding the pub landlord's actions.