Anna’s wish to put her own interests first—specifically to live independently of Kate and to stop serving involuntarily as Kate’s donor—and her incompatible desire to put Kate’s interests first form the central conflict of the novel. The trial, which takes up a considerable portion of the novel’s plot, centers on resolving this conflict. For most of the trial’s length no easy distinction can be made between which is right and which is wrong. Anna has no legal obligation to donate her kidney, which would require surgery and carries a risk of health problems. Yet without Anna’s kidney, which Anna can live without, Kate will die. Several of the characters struggle throughout the book to determine which is the right solution, with different characters arguing different sides of the point, but no one can come up with an argument that settles the issue completely. Only when Anna reveals Kate’s wish to die, making it clear that even Kate does not want Anna’s kidney, does Judge DeSalvo issue a ruling.
Relationships between sisters appear repeatedly in the book, in the characters of Anna and Kate, Sara and Zanne, and Julia and Izzy. In each case, the sisters share an intense bond. Often they rely on each other for support, evident when Zanne visits to take care of Anna and Jesse, or in Julia allowing Izzy to move in with her. Sometimes that support just means one sister listening to the other’s thoughts or problems, as we see each pair of sisters do multiple times in the novel. In the case of Anna and Kate, however, their bond is both more intense and more strained than those of the other pairs of sisters because of Anna’s role as a donor to Kate. From birth, Anna has served as Kate’s savior in addition to being her sister. Both girls recognize this fact. Kate, though she often behaves as any big sister would, also shows immense gratitude to Anna. But Anna’s blood literally flows through Kate’s veins. Anna, for better and worse, feels so strongly connected to Kate that she compares their relationship to that of Siamese twins at one point. Her metaphor suggests that not just their lives, but also in a very real way their bodies as well, are interconnected.
Several characters in the story keep secrets from the rest of the world. Campbell hides his epilepsy and his real reasons for breaking off his relationship with Julia, Anna disguises her real motivation for filing her lawsuit, and Jesse conceals his acts of arson. In doing so, each character satisfies a deeper motive: Campbell doesn’t want to feel vulnerable or invite pity; Anna doesn’t want to reveal Kate’s wish to die; and Jesse doesn’t want to be found out, as much because he doesn’t want to have to discuss the feelings spurring his delinquency with his parents as because he doesn’t want to be punished. In each instance, the character prevents other people from knowing the real motivation for her or his actions, creating a discrepancy between what people think the motivation is and what the motivation actually is. Brian hints at this discrepancy when he speaks about dark matter, which, because it emits no light, cannot be seen directly, though it can be measured by the gravitational pull it has on the objects around it. In other words, the characters in the novel create a contrast between their appearances and their true feelings and actions.
Again and again Campbell gives different, often laughable explanations for his service dog, Judge. He tells people he has an iron lung, that he has SARS, that he is color-blind. These answers serve as diversions, intended to point other characters, as well as the reader, away from the truth, and they act as one of the most prominent examples in the novel of a character concealing his feelings and motivations. Campbell won’t even tell Julia why he needs Judge, when the reason he has Judge—his epilepsy—was his main reason for breaking off his relationship with her when the two were younger. But Campbell’s bond with Anna and the rekindling of his romance with Julia challenge this self-defense mechanism. After Campbell has a seizure in the courtroom, he finally reveals that Judge is an epilepsy dog that can sense when Campbell is going to have convulsions. Campbell’s admission counts among the different examples of characters revealing the reasons for their secrets.
When the narrative shifts to Brian’s perspective, he frequently talks about the stars. For Brian, astronomy offers a break from the stresses of his work and family as well as providing him with a frame of reference for understanding the difficult situation his family is in. When Anna stays with Brian at the firehouse, for instance, he asks her to go to the building’s roof with him so they can watch a meteor shower. He thinks to himself that when they wish on falling stars, what they see is really just a trail of burning debris, implying that Brian believes it futile to wish on the falling star. Yet he also uses the experience as a chance to bond with Anna, and when Anna says she knows that Brian wants to ask her about the lawsuit, he tells her she doesn’t have to say anything and turns his focus back to the stars. In another instance, Brian points out the star Vega, which is part of the constellation Lyra, named for Orpheus’s lyre. Orpheus, Brian tells Anna, loved Eurydice so much that he wouldn’t let death take her away. The story clearly brings Kate to mind for both Brian and Anna. In addition, we learn that Sara and Brian even named Anna after Andromeda, which is a constellation as well as the name of a galaxy visible in that constellation.
At several points in the book, old family photographs lead characters to recall the past and reflect on the situations they presently find themselves in. Kate, for instance, looks at a picture of herself as a baby and, recognizing the sickly cancer patient she has become, wonders who that child is. Anna notes that people take childhood photographs as proof that time has passed and that they were happy once, in contrast with the pain her family feels now. At the end of the book, Kate and Sara spend hours looking at a picture of Anna, whose death made Kate’s survival possible. Often members of the family, notably Sara and Brian, will look back on these family photos and think about how those earlier versions of themselves and their loved ones seem like strangers now. The motif works to emphasize how drastically the family has changed, always for the worse, in the years since Kate became sick.
Fire symbolizes the relationships within the Fitzgerald family, evidenced in part by Picoult’s choice of Carl Sandburg’s poem “Kin” as the epigraph for the opening chapters. The poem describes fire’s ability to warm as well as to consume, just as the relationships we see in the family, particularly that of Anna and Kate, can both nourish and destroy. Anna and Kate emotionally sustain each other, for instance, even as Anna undergoes painful medical procedures in order for Kate to survive. At the same time, Kate feels increasingly wasted and consumed by her struggle to remain alive, and to a great degree no longer wants to be sustained. Moreover, Anna compares her decision to file the lawsuit for medical emancipation with giving fuel to a fire. Another of the epigraphs Picoult chooses, the poem “First Fig” by Edna St. Vincent Millay, talks about a candle burning at both ends. The family, like that candle, is metaphorically burning itself out.
More than any of the other characters, Jesse and Brian display particular preoccupations with fire. Jesse turns out to be the arsonist setting fires all over the city, while Brian, a career firefighter, earns his living putting fires out. Although Jesse and Brian approach fire in different ways, fire means essentially the same thing to both of them. They view it as a destructive and essentially uncontrollable force, and in that sense fire to them serves as a symbol of Kate’s cancer and the effect that cancer is having on their family, which is figuratively burning out. Just as Brian puts out actual fires at work, he tries at home to put out figurative fires, such as the emotional problems Anna has in response to Kate’s health and Jesse’s negative behavior in reaction to Kate. Jesse’s destructive acts, notably his setting fire to several buildings, stem from his overwhelming sense of guilt over his inability to save Kate. His feeling of powerlessness regarding Kate’s cancer turns into rage, which he releases by burning down buildings. For Jesse, fire also serves as a way to gain his father’s attention, albeit indirectly. Jesse feels neglected because his parents focus so much on Kate, but by setting fires he can literally call his father’s attention any time he chooses.
Stars and dark matter function as separate, but related, symbols in the novel. Because stars emit light, we can see where they are and how they move. But dark matter, as Brian explains to Julia, can’t be seen. We only know it exists because we can measure the gravitational effect it has on the visible objects, including stars, around it. Similarly, the references to stars in the novel, which come predominantly from Brian, relate to the general situations characters find themselves in. When Brian talks about twin stars, for instance, and how the light from one star can be so bright that it obscures the light of the other star, the metaphor clearly points to the relationship between Anna and Kate. Because her illness draws so much of their parents’ attention, Kate figuratively obscures Anna’s presence. In another example, we learn that Brian and Sara named Anna after the constellation (and galaxy) Andromeda, said to be located in the sky between her mother and father. Anna, similarly, has one parent on either side of her in her court battle, with one supporting her decision and one fighting it. Furthermore, in Greek mythology, Andromeda’s parents sacrificed her to save their country, much as Anna’s parents force Anna to make sacrifices to save Kate, and to a large degree, their family.
Dark matter, on the other hand, refers to the hidden motivations influencing the behavior of the characters. For Anna, that motivation is her desire to fulfill Kate’s wish to die, which prompts Anna to file the lawsuit at the center of the novel. For Jesse, the metaphor pertains to his feelings of guilt over not being able to save Kate and his desire for more attention from his parents, both of which lead him to start setting fires. For Campbell, the wish to hide his epilepsy motivates him, causing him to lie about his need for a service dog and providing the reason he ended his relationship with Julia when they were younger. In each case, the characters try to keep their motivations hidden, but those motivations still show themselves in the behavior of the characters, just as an observer can detect the presence of dark matter by its effects on its surroundings.
More than her baldness or the scarring on her skin, Kate’s central line, meaning the catheter protruding from her chest that serves as the main port into Kate’s body for her treatments, symbolizes her cancer. Repeatedly in the novel, characters note the presence of Kate’s central line. For instance, when Kate receives her first dose of cord blood, harvested from Anna’s umbilical cord just moments after her birth, Sara watches the doctors connect the bag to the central line. The most notable episode involving Kate’s central line occurs when Kate, Anna, and Sara shop for Kate’s prom dress. Kate becomes frustrated because the dresses are cut too low. When the saleswoman, thinking Kate’s concern is that she doesn’t want to show too much skin, suggests a dress that will cover what she calls “a fair amount of cleavage,” Kate becomes angry. Kate opens the top of her blouse revealing the catheter sticking out from her chest and asks the saleswoman if the dress will cover it.