Roland is the last gunslinger of Mid-World, a knight-like figure trained from childhood to protect his fading world. Having lost two fingers on his dominant hand and suffering from a severe infection, he is in a race against time. He follows the directives of a mystical tarot reading to gather three companions for his lifelong mission to find the Dark Tower.

Eddie is a 20-year-old from 1987 New York who smuggles drugs to appease a local crime boss. He uses sarcasm and pop-culture references to deflect from his deep anxieties and drug withdrawal symptoms. Despite his poor choices, he possesses a strong protective streak, especially regarding his older brother.

Odetta is a wealthy 26-year-old civil rights activist in 1964 New York. She uses a wheelchair following a severe injury on a subway track. Unbeknownst to her, trauma has fractured her mind into two distinct identities: the calm, intellectual Odetta, and the fiercely aggressive, amoral Detta Walker. She regularly loses periods of time when her alternate identity takes over.

Jack Mort is a seemingly ordinary accountant living in 1977 New York. Behind his polite exterior in his blue suit and gold-rimmed glasses, he is a sadistic serial killer. He derives intense pleasure from a practice he calls depth-charging, which involves secretly pushing unsuspecting victims into fatal accidents.

Henry is Eddie's older brother, a veteran traumatized by his service in the Vietnam War. He initiated Eddie into using heroin and consistently uses Eddie's loyalty to shield himself from the consequences of his actions. He is held as collateral by a crime syndicate.

Balazar is a ruthless and paranoid crime boss operating out of a neon-lit building in New York. He forces desperate individuals into running drugs for him by holding their loved ones hostage.

Jake is a 12-year-old boy from another timeline who became Roland's travel companion. Roland allowed him to fall to his death in exchange for information, a decision that leaves the gunslinger in a state of spiritual stasis and profound guilt.

Also known as the man in black, Walter is an antagonistic figure who placed Roland in a ten-year sleep. He drew the three tarot cards that dictate Roland's current mission to find the prisoner, the lady of shadows, and death.

A loyal enforcer working for Balazar. He suspects Eddie of cooperating with federal agents and closely monitors his movements to ensure the crime syndicate is protected.

Roland's former weapons master and mentor. He taught the young gunslingers a punishing code of masculinity and survival that Roland heavily relies on during moments of crisis.

An observant airline employee who notices Eddie's sudden change in eye color and odd requests. She stays alert to his suspicious behavior during the flight, preparing to intervene if necessary.

Odetta's professional chauffeur. He is protective of his employer and politely ignores the strange gaps in time when she mysteriously disappears for days.

A medical intern assigned to emergency paramedics. He treats Odetta after her horrific subway injury and is deeply unsettled by her sudden, aggressive personality shifts in the hospital.

Odetta's father, a wealthy and successful businessman. His financial influence provides Odetta with a layer of protection during her civil rights activism in hostile territories.

A New York pharmacist whose store appears magical to a dimension-hopping visitor. He is held at gunpoint for life-saving antibiotics.

One of Balazar's heavily armed enforcers. He attempts to intimidate Eddie into handing over the smuggled goods.

A criminal working for Balazar who keeps Henry heavily sedated with forced heroin injections.

Another of Balazar's men who torments Henry while keeping him imprisoned.