If we had to pick a main character out of the seven narrators in this book, kind of like picking a kickball captain, we'd pick Anna. She's the first voice we hear, and the whole court case that drives the plot centers on her. This plucky thirteen year old was "born for a very specific purpose" (1.1.3)—to donate blood (and later, a kidney) to her sister, Kate, who has leukemia. She's basically the human version of factory-farmed beef. A McDonor, in other words.
At the beginning of the book, Anna hires Campbell Alexander because she wants to sue her parents. She wants to control her own medical decisions, and he works with her to get medical emancipation. If they can pull it off, she'll no longer have to donate a kidney unless she wants to, no matter what her mom says.
This feud over a kidney (girl, you have two) ends up tearing the Fitzgerald family apart. A lot of the drama comes from the fact that Anna feels invisible. She feels like she isn't your typical teenage girl with boy problems, a hockey game to practice for, and homework to do, and instead her mom, Sara, sees her only as a donor. Being seen as simply a mass of cells to keep someone else alive makes Anna feel less than human.
It doesn't help that the whole family seems to speak in metaphors all the time. When Anna plays hockey, she tries really hard because, as she says, "I don't like letting a whole team down" (3.5.39). In case you didn't make the connection, a family is also a team, and Anna is constantly fretting about letting them down.
To make matters worse, when her mom sees her play, she notes, "Anna saves, every time" (6.4.33). They put so much pressure on their thirteen-year-old daughter to pretty much hold the family together, and Anna is sick of being glue. She just feels stuck. (Oh man, we're speaking in metaphors now, too.)
It turns out that, in one of Picoult's trademark twist endings, Kate wants Anna to do this because Kate wants to die. She's sick and tired of being sick and tired. Anna gets her emancipation proclamation in the end, which is what she wanted all along, but it puts her in a toughsituation. As she says, "Even if we win, we don't" (7.2.12)—because, you know, no one wants to be responsible for their sister's death.
Speaking of dying sisters, this doesn't end like you'd expect it to. Anna ends up dying in a sudden car accident at the final hour of the book. Her kidney is given to Kate, and Kate survives. We went through the whole book for that? Seriously—way to toy with us, Picoult.
At least we get to know Anna before she dies, which is more than we can say about her parents. As we said, her mom, Sara, pretty much sees her as a walking meat sack. Her dad, Brian, pays a little more attention to Anna—and lets her stay at the fire station where he works—but even he realizes that they took Anna for granted. He says, after Anna's death, "the first one shines so bright, by the time you notice the second one, it's really too late" (10.8.21). He's talking about stars, but he's really talking about his daughters. And by the time you see the light of a star, the star itself is usually dead. Like Anna. (Sorry… too soon?)