Mark is a local historian and academic whose quiet life is interrupted when he witnesses a strange brawl and later connects it to a series of mysterious deaths. Skeptical but deeply inquisitive, he cannot simply ignore the strange coincidences surrounding an old inn called the Pale Horse. His strong sense of justice drives him to act as an amateur investigator, stepping far outside his comfortable scholarly routines.

Ginger is a feisty, headstrong, and resourceful young woman whom Mark meets through a church festival connection. Unlike Mark's other friends, she is immediately enthusiastic about his theories and fearlessly volunteers to help him investigate the Pale Horse. She brings a practical, street-smart approach to their partnership, perfectly balancing Mark's academic mindset.

Detective-Inspector Lejeune is the primary law enforcement officer assigned to investigate the brutal killing of Father Gorman. Careful, open-minded, and dedicated to justice, he takes the investigation seriously rather than dismissing unusual clues. He manages official police efforts while occasionally comparing notes with Mark's amateur investigations.

Thyrza Grey is a spiritualist who resides at a historic former inn known as the Pale Horse alongside her two companions. Outwardly appearing as a rational, efficient country spinster, she openly discusses her belief in the occult, elemental powers, and the human death drive. She serves as the charming but unnerving hostess of the inn, blending traditional superstitions with modern ideas.

Ariadne Oliver is a celebrated author of mystery novels and an anxious, somewhat eccentric recluse. As a close friend to Mark, she acts as a sounding board for his strange discoveries. Her experience constructing fictional mysteries gives her a unique, practical perspective on the bizarre events unfolding around them.

Father Gorman is a kind and well-regarded local Catholic priest. His dedication to his parishioners leads him out into a dreary, foggy night to hear a dying woman's confession. The shocking secrets he learns during this final rite put him in immediate danger, and the scrawled list of names found on his person becomes the central puzzle of the narrative.

Mr. Osborne is a local pharmacist whose shop sits along the street where Father Gorman was killed. He prides himself on his keen memory for faces, a skill he claims to have honed over years of observing customers. He provides the police with a detailed description of a distinct man he saw following the priest in the fog.

Hermia is Mark's closest friend and frequent date. Cultured and highly rational, she is entirely dismissive of the supernatural and refuses to help Mark investigate the strange coincidences surrounding the Pale Horse, finding his sudden obsession to be silly and unreasonable.

Mr. Venables is a fabulously wealthy collector who lives a life of leisure after retiring due to a severe struggle with polio that left him confined to a wheelchair. He harbors philosophical beliefs about the tangible reality of evil in the modern world, and his distinct physical appearance makes him a subject of police interest.

Rhoda is Mark's cousin, a local resident who provides him with the initial background information about the Pale Horse. She explains the inn's current occupants and their reputation for spiritualism, setting Mark on his path to visit the establishment.

Bradley is a man based in Birmingham who operates on the fringes of the law. Operating under the guise of a bookmaker, he sets odds on the lifespans of specific individuals, serving as the financial and logistical go-between for those seeking the services of the Pale Horse.

Mrs. Calthrop is the local vicar's wife and a thoughtful, grounded presence in the community. When Mark unburdens his fears about the list of names and the Pale Horse, she offers him serious, prayerful support, agreeing that whatever wicked events are unfolding must be stopped.

Sybil is a resident of the Pale Horse who operates as a medium. She maintains an exotic appearance, often wearing a sari, and speaks of her travels to places where voodoo and witchcraft are practiced, contrasting heavily with Thyrza's more practical English demeanor.

Bella serves as the cook at the Pale Horse and is openly described by locals as a witch. She is a strange, silent, and dark figure who participates heavily in the inn's unsettling rituals, bringing a primal and frightening energy to their ceremonies.

Poppy, whose real name is Pamela Stirling, is an employee at a local florist shop. During a dinner conversation about witches, she is the first to mention the Pale Horse and its dangerous reputation, though she quickly becomes terrified and refuses to speak further on the matter when pressed.

Thomasina is a young woman whom Mark observes in a violent altercation where a handful of her hair is torn out. Her sudden death shortly after this event, combined with her name appearing in the obituaries, serves as the initial catalyst for Mark's investigation.

Mrs. Tuckerton is Thomasina's bitter and miserly stepmother. She stands to inherit the family fortune following her stepdaughter's passing and exhibits extreme, pale terror when Mark casually mentions the Pale Horse during their conversation.

Mrs. Davis is a dying woman who urgently requests the presence of a Catholic priest. Her final confession contains shocking details about wickedness and a specific list of names, placing a terrible burden on Father Gorman moments before he is killed.

David is a friend of Mark's who joins him for dinner after a theater production. He holds a casual but firm belief that witches still exist in rural English villages, unwittingly steering the group's conversation toward the occult.

Jim is a college acquaintance of Mark's. He helps Mark establish that one of the names on Father Gorman's list belonged to his own godmother, though he refuses to get directly involved in investigating the Pale Horse.

Colonel Despard is Rhoda's husband. He describes the current occupants of the Pale Horse to Mark, noting that Thyrza Grey is highly involved in the occult and framing the old inn as a bizarre local curiosity worth visiting.