Thirteen-year-old Anna Fitzgerald begins narrating the story, which will continually alternate among different first-person narrators, in the present. She talks about the different reasons babies come into being and admits that she was born for a very specific purpose. Scientists used her mother’s eggs and father’s sperm to create a specific combination of genes. They created her in this way so she would be able to save her sister, Kate. Anna talks about visiting a pawnshop to sell a locket. She has a difficult time parting from the locket because her father gave it to her as a gift after she donated bone marrow to Kate. Anna goes on to describe herself as skinny and a freak. She talks about her family, how her sister Kate has leukemia, and how she has had to undergo medical procedures to help Kate whenever Kate has gotten sick. Her mother, meanwhile, obsessively shops online, and her older brother, Jesse, behaves like a delinquent because their parents don’t have time to care about him.
Anna shows Jesse a newspaper clipping about a lawyer named Campbell Alexander. Jesse warns her not to mess with the system and the roles everyone in the family has, but he still agrees to drive her to Campbell’s office. Anna meets Campbell and notices he has a service dog, which Campbell sarcastically tells Anna prevents him from getting too close to magnets, because he has an iron lung. Campbell tries to send Anna away, and she explains that she wants Campbell to help her sue her parents for the right to her own body.
Campbell gives his account of his meeting with Anna. He talks with her about her case and notices how angry she seems. He agrees to represent her because he thinks the case will be easy to win and great publicity. He doesn’t think they will even need to go to trial, because Anna’s parents will give in before that. Anna leaves after Campbell tells her he will file a petition in family court for her medical emancipation. Campbell’s assistant, Kerri, expresses her shock that Campbell is representing Anna. She wonders where Anna will live during the trial, but Campbell hasn’t thought about it. Campbell’s dog, Judge, pushes against him, apparently alerting Campbell to something. Campbell goes back into his office and locks the door.
Sara’s narration jumps back in time to 1990. While bathing Kate and Jesse, Sara talks to Brian, her husband and a career firefighter, and she recalls her decision to give up her career as an attorney to become a stay-at-home mother. Sara notices a bruise on two-year-old Kate’s shoulder blade. The next morning, bruises have spread up and down Kate’s spine. Sara takes Kate to the hospital where Kate undergoes a series of tests. The hospital refers Sara to an oncologist who, after further tests, diagnoses Kate with acute promyelocytic leukemia (APL), a rare and aggressive form of blood cancer. The doctor tells Sara and Brian that APL has a twenty to thirty percent survival rate and they should begin treating Kate immediately. At home Sara and Brian deal with the fallout of the diagnosis and the realization that their daughter may not survive. Sara refuses to let Kate die.
In the present day again, Brian Fitzgerald describes a fire at a medical school. The fire started because a body got stuck in the cremation incinerator. He turns the story to earlier that night, while he ate dinner with his family. Kate upsets Sara because she wears a t-shirt with a picture of a crab and the word “Cancer” across it. Jesse walks in reeking of pot. Finally Anna arrives, and Brian immediately notices something is wrong. Anna remains quiet and withdrawn through the meal, and she does not have her locket on. She leaves the table without saying a word. After dinner, Brian and Sara discuss their daughters. Sara talks about Kate, but Brian worries about Anna. Sara mentions that she has to take Kate to dialysis the next day. Later that night, Anna visits Brian at the station. She doesn’t want to talk, but together they watch the stars from the station’s roof.
The epigraph, Carl Sandburg’s poem “Kin,” sets up the symbol of fire and the theme of kinship, both of which will continue throughout the novel. In the poem, the speaker says he will warm his brother, wrap him up, use him, and change him, in the same way that fire warms the kindling as it envelops and ultimately burns it, using it up and changing it. The poem talks about kinship’s nurturing, destructive, and transformative powers, all of which the reader will see in the relationships within the Fitzgerald family. This complex dynamic describes Anna’s and Kate’s relationship in particular. Anna’s role as a donor to Kate uses her up, emotionally and physically to a degree, even as it sustains Kate. Anna instigates the lawsuit because she no longer wants to play this role.