The Midwife's Apprentice is narrated in third person ("she said," as opposed to "I said," which is first person), using a limited omniscient viewpoint (in which only the protagonist's thoughts and feelings are revealed). The novel is set in medieval England.
Brat, the protagonist, or main character of the novel, is a homeless, nameless young girl who might be twelve or thirteen years old (she doesn't know her exact age). Brat has no memory of her parents. For as long as she can remember, she has lived on her own, going from village to village, stealing food or working in exchange for food or a dry place to sleep. One morning, she is discovered sleeping in a warm pile of dung by the village midwife. Brat calls the midwife "Jane Sharp," because she has "a sharp nose and a sharp glance." The midwife calls her "Beetle" and takes her in to work as her servant. In return for her labor, Beetle receives scraps of food and a place to sleep. Even though the midwife is mean to Beetle (slapping Beetle and calling her names), Beetle considers her situation a step up from living on the streets and sleeping in dung. She now has work and a place to live.
Soon, Beetle befriends a stray cat that she rescues from the inhumane treatment of the village boys. Even though she doesn't know how to sing songs or speak gently to the cat, who is close to death, she feels compassion and is relieved when she realizes the cat will live. Beetle begins to give the cat scraps of food she saves from her meager meals and the cat begins to follow her wherever she goes. Later, she names the cat Purr.
Beetle continues to follow the midwife from cottage to cottage, preparing and carrying the midwife's supplies. But Beetle is never allowed to watch the midwife or to learn what the midwife is doing when she helps to deliver a baby. Because she is curious, Beetle watches covertly — looking through cracks in the windows or standing in the shadows of a room out of the midwife's sight. Beetle begins to gain some self-esteem. This becomes evident when she goes to the Saint Swithin's Day Fair for the midwife, to replenish the midwife's supplies. During the course of the day, Beetle is treated with respect. She is complimented, given a comb, and is mistaken for someone who can read. She renames herself "Alyce," and thinks that someone named Alyce could be loved.
Back in the village, Alyce is adamant about people calling her "Alyce" and not Beetle. She thinks better of herself and, consequently, acts better. She saves Will, a bully from the village who has always picked on her, from drowning in the river and later helps him deliver twin calves. Alyce finds a homeless boy sleeping in the barn near Will's cow and calves. She feeds him, helps him name himself (giving him a bit of self-respect), and sends him to the manor to find work.
As time passes, the villagers begin to accept Alyce and ask her advice. She earns their respect when she successfully delivers a baby in the mid-wife's absence. For possibly the first time in her life, Alyce feels pride and smiles. Although Alyce is happy about her accomplishment, the midwife is not. The midwife is angry because she doesn't want competition from Alyce. The midwife is even more upset when a woman in labor asks for Alyce and not for her. When Alyce realizes she can't deliver the baby because it is a difficult birth and she doesn't know what to do, she has to call for the midwife to come to deliver the baby. She is totally humiliated. Feeling like a failure, Alyce takes Purr and runs away.
Alyce is depressed. She doesn't think she can return to the village. She and Purr arrive at an inn situated at a crossroads. Alyce trades her labor for food and shelter. While working at the inn, Alyce is taught by one of the patrons of the inn to read, and she learns what she wants in her life. What she really wants is to be the midwife's apprentice. A self-respecting Alyce returns to the midwife in the village and asks to be her apprentice once again, vowing never to give up.