Philip Marlowe is a resourceful and cynical private investigator operating in Los Angeles. Often struggling to find paying clients, he possesses a sharp eye for detail and a sarcastic demeanor. He relies on his street smarts, physical endurance, and occasionally alcohol to extract information from unwilling subjects. He maintains a strict personal code of conduct, which frequently puts him at odds with the corrupt local police forces.

Moose Malloy is a massive man who recently finished serving an eight-year prison sentence for a solo bank robbery. He dresses in noticeably large, flashy clothing and possesses immense physical power. He is singularly focused on tracking down his former fiancé, who disappeared while he was incarcerated. His refusal to let the past go drives him through the city on a destructive and relentless path.

Helen Grayle is the striking, wealthy wife of an older multimillionaire. She lives a lavish lifestyle in a heavily guarded estate and freely engages in extramarital affairs. After her valuable jade necklace is supposedly stolen during a highly publicized heist, she crosses paths with Philip Marlowe. She uses her wealth and physical attractiveness to manipulate the social and political circles of Bay City.

Anne Riordan is a twenty-eight-year-old orphan who lives alone in Montemar Vista. As the daughter of a former Bay City police chief, she possesses a natural aptitude for investigation and an easy rapport with law enforcement. She takes an active interest in Marlowe's case after finding a body on the beach. She frequently offers him crucial insights and a safe place to theorize away from the corrupt police force.

Lindsay Marriott is a wealthy, well-dressed man who resides in the upscale neighborhood of Montemar Vista. He previously worked in radio and harbors acting ambitions, cultivating relationships with affluent women in the area. He hires Marlowe to act as a bodyguard during a ransom exchange for a friend's stolen jewelry, though he is noticeably anxious about the arrangement.

Velma is a former night club singer and the long-lost fiancé of Moose Malloy. Eight years prior to the events of the story, she worked at Florian's when it was a white establishment. Her current whereabouts are entirely unknown, making her the central figure in Malloy's frantic and violent search through the city.

Randall is a sharp, capable detective from Central Homicide in Los Angeles. Unlike many of his local colleagues, he demonstrates genuine investigative skill and a keen eye for details. He maintains a tense but mutually respectful dynamic with Marlowe, frequently warning the private investigator to stay out of official police business while occasionally sharing theories.

Nulty is a lean-jawed, cynical police detective who handles the initial investigation at Florian's. Feeling overworked and unappreciated by his department, he lacks the motivation to conduct a thorough search for Moose Malloy himself. Instead, he attempts to leverage Marlowe into doing the investigative legwork for free.

Jessie Florian is the widow of the former owner of Florian's bar. She lives in a rundown home and suffers from severe alcoholism, which makes her both vulnerable to manipulation and emotionally volatile. She harbors old photographs and hidden knowledge about the bar's past employees, sustaining herself partly through a mysterious monthly stipend.

Jules Amthor operates as a "Psychic Consultant" from an isolated, modernistic home in Stillwood Heights. He possesses an ageless, ethereal appearance with unnervingly expressionless eyes. He caters to wealthy clients but quickly demonstrates a capacity for ruthless violence when his business operations are threatened.

Dr. Sonderborg runs a shady, secretive medical facility housed within an old residential building. He colludes with corrupt police officers to quietly detain and drug individuals who pose a problem for the city's power brokers, operating entirely outside legal bounds.

Golbraith, nicknamed "Hemingway" by Marlowe, is a large Bay City police officer. While he participates in corrupt practices under the orders of the city's political machine, he views himself as a decent man trapped in a broken system and occasionally exhibits moments of candor.

John Wax is the Chief of Police in Bay City. He is heavily influenced by the wealthy elite and political donors, readily adjusting his law enforcement priorities to accommodate the demands of the city's upper class, particularly families like the Grayles.

Laird Brunette is a powerful gambler who operates a fleet of offshore gambling boats beyond the reach of local law enforcement. He is reputed to financially control the Bay City political system, operating strictly as a practical businessman rather than a violent thug.

Red is a rough, observant sailor who operates a discrete water taxi service. He possesses extensive knowledge of the offshore gambling operations and assists Marlowe in infiltrating Laird Brunette's ship, openly expressing a deep disdain for the corrupt men who run the town.

This unnamed man serves as Jules Amthor's bodyguard and natural medium. He has a powerful physique and brutally assaults Marlowe on Amthor's command, utilizing immense physical strength to subdue him.

Captain Blane is a corrupt Bay City police officer who works alongside Golbraith on the vice squad. He is known among his peers for being overly eager to use excessive physical force during his assignments.

Mr. Grayle is an elderly, wealthy man worth roughly twenty million dollars. He owns a local radio station and appears frail and quietly defeated, passively accepting his younger wife's blatant extramarital affairs without outward protest.

Old Nosey is Jessie Florian's nosy neighbor. She pays close attention to the comings and goings at the Florian household, including Jessie's mail and visitors, though her willingness to share information fluctuates based on her moral judgments of the inquirer.

The bouncer at Florian's tries to enforce the bar's current segregation policy by turning Moose Malloy away. This attempt leads to a sudden and lethal altercation with the massive ex-convict.