Will is a middle-aged, retired lawyer living in North Carolina after a successful career in New York City. Widowed following the death of his wealthy wife, Marion, he begins experiencing unusual physical falls and intense memories of his past. He suffers from a profound existential depression, leading him to obsess over absolute answers about the existence of God and the meaning of life. He spends his days playing golf while quietly contemplating suicide as a rational response to the world.

Allison is a young woman who recently escaped from a psychiatric hospital after receiving electro-convulsive therapy, which erased most of her memories. She moves into an abandoned greenhouse owned by her late aunt, seeking quiet independence away from the expectations of her wealthy family. She struggles to understand modern language and social cues but proves highly capable when working with her hands and solving practical problems.

Kitty is Will's former romantic partner from his youth and Allison's mother. Now married to a dentist, she is an attractive, confident older woman who retains a strong lust for life. She holds overbearing expectations for her daughter and believes Allison is completely incapable of surviving outside of a psychiatric institution.

Leslie is Will and Marion's daughter, who has recently become a born-again Christian. She is highly practical and often appears stern, viewing her faith as a crisp business transaction rather than an emotional connection. She intends to use her late mother's fortune to aggressively fund Christian organizations and retirement communities.

Marion is Will's late wife and the heiress to a massive fortune. She was a woman with disabilities who found comfort in northern Episcopal Christianity and doing good works. Over the years, she gained a significant amount of weight, and her marriage to Will grew increasingly distant before her premature death.

Vance is Will's friend and golfing partner, who also serves as a medical confidant. He checks on Will's physical and mental well-being, attempting to diagnose the strange falling spells and memory lapses that plague him.

The psychiatrist who treats Allison at the hospital. He attempts to use knock-knock jokes to help her with her speech issues and communicates directly with her parents regarding her legal competency.

The local Episcopal priest who hints that Will should use Marion's vast fortune to fund a Christian retirement community. Will often views him skeptically as a sort of religious swindler who uses faith to solicit funds.

A local neighbor and poacher whom Will remembers from childhood. He represents to Will the uncivilized, wild aspects of white Southern society and casually invites Will to watch adult films.

Allison's late aunt. She leaves behind a ruined house and an intact greenhouse near a golf course in North Carolina, which provides Allison with a crucial destination for her escape.

One of Will's golfing companions. He introduces Will to the old cave that once held a saber-toothed tiger skeleton, inadvertently providing Will with a location for his dark experiment.

A man who struggled deeply with depression and despair, eventually dying by suicide when Will was young. Will remembers an incident where his father seemingly attempted to shoot him, shaping Will's belief that his father loved only death.

Kitty's brother and Will's old associate. Will mails him a letter detailing his drastic plans and insurance policies, relying on Sutter to execute his final wishes and handle his affairs.

The man engaged to marry Leslie Barrett. He remains largely in the background as Leslie plans their life and the Peabody Foundation.

A dentist married to Kitty Vaught Huger. He travels with her to North Carolina but remains a distant figure, as Kitty admits she plans to divorce him.