Margery is a 46-year-old home economics teacher in post-WWII London. Frustrated by her dull life and mocked by her students, she decides to pursue her childhood dream of traveling to New Caledonia to find an undiscovered golden beetle. She is methodical, sensible, and emotionally repressed due to early life trauma, often wearing dowdy suits and lacrosse boots for her expedition.

Enid is a petite, blond woman in her twenties who wears flashy clothes, heavy makeup, and painted nails. She acts as Margery's expedition assistant despite lacking conventional qualifications. As a highly talkative young woman who carries a mysterious red valise, Enid operates by her own rules and repeatedly demonstrates an impressive ability to acquire necessary supplies through unorthodox means.

Mundic is a gaunt veteran of World War II and a former prisoner of war in Burma. Suffering from severe trauma and malnutrition, he struggles to distinguish past horrors from present reality. After Margery rejects his application, he becomes fixated on her expedition, convinced that she requires his military expertise to survive the jungle.

Mr. Benson is a mild-mannered clergyman who spends most of his days reading. He introduces his daughter to the wonders of natural history, sparking her lifelong passion for entomology. The devastating loss of his sons in World War I shatters his mental state and forever alters his family's trajectory.

Mrs. Pope is the wife of the British consul in New Caledonia and the unquestioned leader of the local social clique. She strictly adheres to polite society rules, wearing sheer stockings and formal attire despite the extreme tropical heat. She initially abandoned her own dreams of acting to conform to societal expectations, making her highly critical of women who flout convention.

Professor Smith is a dedicated entomologist at the Natural History Museum in London. He takes Margery seriously when she is a young girl, encouraging her research and treating her dream of finding the golden beetle with professional respect.

Taylor is a passenger who strikes up a romance with Enid during their sea voyage. He lives in a detention camp in Brisbane and exhibits highly controlling behavior, keeping a gun and attempting to aggressively restrict Enid's movements and finances.

Dolly Wiggs is a resident of New Caledonia who operates on the fringes of Mrs. Pope's social circle. She proves to be an independent thinker who provides crucial assistance and medical help to Margery when the expedition runs into trouble with the authorities.

Freya is a middle-aged entomologist who has spent her career enabling the success of her male colleagues while ignoring her own ambitions. Discovering an anonymous donation of rare beetles sparks a sudden desire to break out of her routine and pursue her own field research.

Mr. Rawlings is a stray dog that Enid adopts in New Caledonia. He accompanies the women on their drive into the mountains and stays with them at their jungle base camp, though his frequent barking creates tension in the quiet environment.

Miss Hamilton is an applicant who initially seems perfect for the expedition, presenting herself as a capable and refined version of Margery. She abruptly cancels her participation after learning about Margery's unusual and chaotic exit from the school.

Mr. Collett is an older veteran who lost a leg during basic training for the war. His severe physical suffering and phantom limb pain deeply impact his marriage and lead to a tragic situation that forces his wife to flee the country.