Marion Praise Stone is the narrator and one of the conjoined twins born at Missing Hospital in Addis Ababa. Named after a famous 19th-century surgeon, he is observant and deeply connected to his brother, Shiva. He spends his early years growing up in the hospital compound, developing an early fascination with medicine by watching the doctors around him. He acts as the verbal spokesperson for himself and his brother during their youth.

Shiva Praise Stone is Marion’s twin brother. Physically identical to Marion but distinctly different in personality, Shiva is intense, quiet, and highly observant. While Marion connects easily with people, Shiva is more withdrawn, showing early brilliance in mathematics and a deep affinity for animals and dance. He shares a uniquely close bond with his brother, frequently communicating without words.

Genet is the daughter of Rosina, the hospital's Eritrean nanny, and Zemui. Raised in the Missing Hospital compound alongside Marion and Shiva, she is an integral part of their childhood. She is headstrong, beautiful, and deeply affected by her Eritrean heritage and her parents' complicated relationship.

Dr. Thomas Stone is a brilliant British surgeon working at Missing Hospital. He is deeply devoted to his medical practice and relies heavily on his surgical assistant, Sister Mary Joseph Praise. Known for his quiet and sometimes surly demeanor, he operates with intense focus. The unexpected birth of his conjoined twin sons plunges him into a profound personal and professional crisis.

Ghosh is an internal medicine specialist at Missing Hospital with expertise in treating sexually transmitted diseases. Known for his optimism and warm demeanor, he brings a lively energy to the hospital compound. He harbors a deep, long-standing affection for his colleague Hema. When the twins are born, Ghosh steps in to provide them with paternal care and guidance.

Hema is an obstetrician and gynecologist from Madras, India, working at Missing Hospital. Fiercely intelligent and independent, she provides critical maternal care to the hospital's patients. She takes immediate charge of Marion and Shiva following their dramatic birth, giving them their names and raising them as her own. Her pragmatic approach to medicine is matched by her fierce protectiveness over the children.

Sister Mary Joseph Praise is a Carmelite nun originally from Madras, India, who travels to Africa to spread the gospel through healing. She serves as a dedicated surgical assistant to Dr. Thomas Stone at Missing Hospital. Quiet and devout, she draws inspiration from Saint Teresa of Avila. Her difficult pregnancy and the subsequent dramatic birth of her conjoined twins serve as the catalyst for the hospital's shifting dynamics.

Matron is a pragmatic Carmelite nun who manages the operations at Missing Hospital. She prioritizes practical medical care and the physical well-being of her patients over strict religious doctrine. With a firm but compassionate hand, she oversees the diverse staff of the hospital, balancing the demands of foreign donors with the immediate needs of the local Ethiopian community.

Rosina is an Eritrean woman who works as a nanny and housekeeper for Ghosh, Hema, and the twins. She provides daily care for the boys alongside her own daughter, Genet. Her life is complicated by her relationship with Zemui, who maintains another family elsewhere, which influences her protective and sometimes volatile nature regarding her daughter's upbringing.

General Mebratu is a military officer leading the Imperial Bodyguard in Ethiopia. He is a frequent visitor to the Missing Hospital compound, often playing bridge with Ghosh. His military ambitions and political maneuvers heavily influence the political climate of Addis Ababa, eventually drawing the hospital staff into the broader conflicts of the country.

Zemui is an Eritrean man who works as the personal driver for General Mebratu. He is the father of Genet and maintains a complex relationship with Rosina, as he has another wife and children outside the hospital compound. His association with the military brings the political tensions of Addis Ababa directly into the domestic lives of the hospital staff.

Almaz is the housekeeper for Ghosh and Hema at the Missing Hospital compound. Originally arriving at the hospital as a patient seeking treatment for a tumor she mistook for a pregnancy, she becomes a permanent fixture in the community. She possesses a steadfast religious faith and maintains a caring, companionable relationship with Ghosh.

Gebrew is the gatekeeper at Missing Hospital. He also serves as a priest in the Ethiopian Orthodox Church. He bridges the gap between the foreign medical staff and the local customs, blending traditional Ethiopian spiritual practices with his duties at the hospital.

Eli Harris is a member of a Baptist congregation in Texas and a major financial donor to Missing Hospital. He visits Ethiopia with intentions rooted in missionary work, believing the local population needs spiritual saving through Bibles. His ideology frequently clashes with Matron's practical, medically focused approach to running the hospital.

Tsige is a local Ethiopian woman whose life intersects with the staff at Missing Hospital. She initially visits the hospital seeking care for her infant, where she forms an early connection with a young Marion. She later runs a local establishment in Addis Ababa, maintaining ties to the hospital community.