Vesta is a 72-year-old widow living in a former Girl Scout camp cabin in the rural town of Levant. Following the death of her husband, Walter, she adheres to strict daily routines in physical and social isolation. When she discovers a note suggesting a murder has taken place on her property, she applies her active imagination to the mystery, constructing an elaborate internal narrative to populate her quiet life.

Charlie is a retriever/Labrador-Weimaraner mix that Vesta adopted from a kennel in Monlith following her husband's death. As Vesta's only companion, he provides her with daily structure and affection. His animal instinct and physical needs ground Vesta in objective reality, contrasting with her increasingly elaborate internal mysteries.

Walter is Vesta's deceased husband, a German epistemologist whose ashes sit in a bronze urn on her bedside table. Throughout their marriage, he was controlling and intellectually condescending, frequently dismissing Vesta's thoughts as overly emotional. Though he is physically absent, his critical, paternal voice remains a constant presence in Vesta's mind.

Magda originates as the supposed victim mentioned in the mysterious note. Vesta quickly fleshes her out into a young, thin Eastern European immigrant who overstayed a summer work visa. Functioning as a blank slate, Magda serves as a vessel for Vesta to safely process her own history of cultural displacement and marital subjugation.

Blake is the first character Vesta actively creates to populate her murder mystery. She pictures him as a shaggy, boastful teenage boy riding a skateboard, serving as the arrogant but perhaps innocent author of the note. Vesta becomes highly protective of her vision of him, even leaving a poetic response addressed to him in the woods.

Shirley begins as an invented persona—a cold telemarketer and Blake's mother—before Vesta projects this identity onto a real woman who accidentally locks her keys in her car. The real Shirley is an overwhelmed, ordinary local resident whose house and mundane life Vesta secretly inspects for clues to her fictional murder case.

Henry originates as a handsome, brutal suspect in Vesta's mind, modeled partly on Harrison Ford and Walter. Vesta eventually assigns this villainous persona to a real-life general store clerk in Bethsmame, a quiet man who suffers from severe facial scarring due to a past accident.

Ghod starts as an abstract, malevolent monster—a "ghoul"—that Vesta creates to represent pure menace in her mystery. She later projects this terrifying identity onto a real-life police officer who pulls her over for speeding, transforming a routine traffic stop into a frightening encounter with her primary antagonist.

Leo is a purely fabricated character in Vesta's mystery, created to serve as one of Magda's two secret lovers. Vesta designs him as a sweet, young, and ineffectual youth, providing a tender alternative to the brutal Henry in her imagined narrative.

Pastor Jimmy hosts a Christian talk radio show that Vesta frequently listens to in her cabin. His broadcasts about divine providence, anger, and forgiveness provide background noise to her isolated life and occasionally intersect with her internal monologues about the mystery.