Captain Penderton is an officer at a Southern army base who is deeply repressed and prone to creating malicious rumors. He possesses an encyclopedic knowledge of facts but lacks the imagination to synthesize them into new ideas. His internal life is marked by cowardice, emotional repression, a propensity toward sadism, and an unacknowledged attraction to his wife's lover. He approaches daily life with petty irritation and a growing, confusing fixation on a quiet enlisted man.

Leonora is a popular figure around the army base, widely known as a good hostess and an excellent sportswoman. She moves through the world with a shallow fearlessness and feels little anxiety or despair. She openly defies her husband's strict expectations and conducts a long-standing affair with her neighbor. Her lack of common sense makes her largely oblivious to the complex emotional currents swirling through her own home.

Major Langdon is a jovial, well-liked officer who embodies what the military society deems normal and acceptable. He is highly concerned with his public image and personal comfort, actively ignoring any abnormality in his domestic life. He maintains a cheerful exterior while largely neglecting his chronically ill wife in favor of his ongoing affair. His worldview relies heavily on conventional roles and simple platitudes.

Alison is a sensitive woman who suffers from chronic physical ailments and profound, unresolved grief. Despite being dismissed as fragile or mad by her husband and peers, she is highly perceptive and recognizes the ugly truths of the base's social dynamics. She finds no comfort in the rigid military society. Her only true companionship comes from her devoted servant, with whom she shares a private world of aesthetic appreciation.

Private Williams is a solitary, quiet soldier who moves stealthily and avoids social interaction with the other enlisted men. Raised in a strict, entirely male religious household, he fears women and operates with almost no conscious self-awareness. He reacts purely on instinct. A single glimpse of a superior officer's wife triggers a silent, consuming behavioral shift that dictates his nightly movements.

Anacleto is the Langdons' Filipino servant and a vibrant anomaly on the rigid army base. He loves theater, classical music, fine fabrics, and dancing. He fiercely protects Alison and openly disdains the other officers and their wives, finding them coarse and cruel. His flamboyant personality and open eccentricity stand in sharp opposition to the repressed atmosphere of the military post.

Lieutenant Weincheck is a nearly fifty-year-old officer who maintains a small apartment filled with books, plants, a cat, and a piano. He provides a rare intellectual and artistic refuge for the few base residents who appreciate culture. He faces forced retirement by the medical board.

Catherine is the deceased infant daughter of Alison and Major Morris Langdon. Born sickly, she lived for only eleven months before passing away. Her brief life and subsequent death permanently fractured her parents' marriage.

Susie is the Pendertons' Black servant who works in their household. She assists Leonora with tasks such as assembling elaborate food trays and maintaining the daily operations of the officers' quarters.

Firebird is Leonora Penderton's spirited horse. He becomes a point of contention between the Pendertons when the Captain takes him for a chaotic, wild ride. This ride dramatically forces the Captain to confront his own terror and experience a rare moment of ecstatic clarity.