The unnamed narrator is a middle-aged woman who leaves her marriage and her work at the Threatened Species Rescue Centre to seek isolation at a Catholic abbey in her hometown. Though she is not religious, she immerses herself in the daily routines of the sisters, taking charge of the gardening and cooking. Her retreat from modern society allows her to escape her anxieties about environmental destruction while reflecting on her past mistakes.

Helen is a former high school classmate of the protagonist who has grown up to become a prominent nun and radical activist. As a teenager, she endured poverty and physical abuse at home while maintaining a fiercely confrontational attitude toward her peers. As an adult, she retains her combative nature as she travels the world protesting environmental crimes and human rights abuses.

The protagonist's deceased mother lives entirely in her daughter's memories. She was a self-sufficient, eccentric woman who loved gardening, composting, and helping marginalized people in their community. Her deep need for privacy and emotional stillness often made her appear mysterious to those around her, including her daughter.

Sister Simone is the abbess who manages the religious community on the Monaro Plains. She handles the practical and administrative burdens of keeping the financially struggling abbey running. She possesses an open-minded approach to faith, allowing the non-religious protagonist to live permanently at the abbey while encouraging her to view prayer as a tool for introspection.

Sister Bonaventure is one of the older, long-serving nuns at the abbey. She works closely with the protagonist in the vegetable gardens and maintains a quiet, observant presence. Her life in the community is heavily defined by her unresolved history with a former nun who left the abbey decades ago.

Jennifer Tully, known as Sister Jenny, is a former member of the abbey who joined alongside Sister Bonaventure in 1983. She eventually left the community to establish a shelter for battered women in Bangkok. Her recovered bones act as a focal point for the abbey's mourning and logistical anxieties.

Richard is a quiet, reliable local man who lives on a property near the abbey. A former high school classmate of the protagonist, he regularly volunteers his time and equipment to help the sisters with heavy labor. He assists the community in managing practical crises, including providing traps to manage an escalating mouse infestation.

Annette is Richard's wife and a resident of the nearby town. She views the isolated, celibate lifestyle of the nuns as unnatural and refuses to visit the community. Her discontentment with her conventional life serves as a point of contrast for the protagonist's newfound peace.

Sister Carmel is a fervent, highly devoted member of the religious community. Her absolute dedication to her faith appalls the secular protagonist, especially after discovering that Carmel left her teenage children behind to join the abbey.

Sister Sissy is a vocal and combative member of the abbey who frequently challenges others on matters of faith. She has a strong need to be proven right and eagerly corrects her peers, creating tension with the protagonist's desire for quiet reflection.

Sister Josephine is a timid member of the abbey who is easily distressed by the harsh realities of rural life. She works alongside the protagonist to manage the gruesome task of burying poisoned mice, leaning on shared humor to cope with the unpleasant work.

Sister Dolores is the youngest member of the abbey, suffering from severe allergies and frequent bouts of homesickness. Her youth and dramatic sneezes occasionally annoy the protagonist, who privately wishes the young woman would leave to experience a full, secular life.

Alex is the protagonist's husband, whom she quietly leaves behind when she relocates to the abbey. Their separation occurs without a dramatic confrontation, simply expanding through distance and time as the protagonist withdraws from her previous life.

Helen's mother is a severely mentally ill woman who raised her daughter in a run-down, isolated house. She frequently subjected Helen to public physical and verbal abuse, an ordeal that stemmed from her frequent, unassisted stints in the local hospital's mental health unit.

Mrs. Bird is a beloved high school teacher from the protagonist's past. She stands out as the only adult who attempted to intervene and protect Helen Parry when the entire class physically attacked the girl, condemning the students for their cruelty before ultimately leaving the school.