Rill is the novel’s other narrator. The eldest daughter of Briny and Queenie, Rill is pronounced the “princess of Kingdom Arcadia” by her doting father (156). Her memories of growing up on the river on the family’s shantyboat keep her true identity alive in moments that threaten her self-identity. Like the majority of her siblings, she is graced with tight blond curls that make her a desirable prize in Miss Tann’s estimate. It is only her age, as she is abducted at 12, and her insistence on staying by her siblings that make her problematic to her captors. She is renamed “May” by Miss Tann and Miss Murphy but does not call herself this until the end of the novel, when she gets back home to the family shantyboat. When it burns, she realizes that her life as Rill is over and that she must become May. Although she adapts to a new life, one of safety and comfort, she always keeps that inner self of Rill Foss alive. It allows her to find her siblings, one by one, except for those who are unrecoverable, such as the infant brother she never met, Gabion (who was adopted too young to remember her), and Camellia (who was murdered). Her memories keep Grandma Judy connected to her and eventually connect her to Avery. This allows the Foss name to have a future, as Avery comes to see her place in that family history.

The Foss siblings’ father is simply described as lean and handsome, an attractiveness that Avery too notes when looking at old photographs of the man she doesn’t know is her great-grandfather. He is a man who lives on the Mississippi and depends on it for sustenance. He has a reputation on land as a gambler and troublemaker, but to the Foss kids, he is giant and a god. He plays music and sings. He bestowed names on his girls that remind him of the river, making them true children of the river and of the Arcadia, the shantyboat that is their family home. He is tough and gets angry rather than sad seeing his wife suffer in the throes of childbirth. He is mistrustful of authority figures and those on land and has to be coaxed to let his wife go to a hospital, even though out of love he does it to save her wife. After his wife’s death and having their children all stolen from them, Briny develops an alcohol addiction. Rill runs away to try and reach him, and she hopes to save him. In the end, he goes down with the Arcadia, drowned like Rill’s life as a Foss living on the river.

The Foss children’s mother is fair-haired and slim, a beauty so enrapturing that she is called Queenie by everyone, including her children. She is the queen of the river—sweet, nurturing, and full of songs and smiles. She dotes on her little ones and loves nothing more than holding a newborn baby in her arms. She ran away from her Polish relatives to take up with Briny, but she still prays in Polish to a Catholic cross. Although Rill doesn’t know any words in Polish, the language connects her to her mother as does the crucifix.

The only brunette Foss sibling, Camellia is seen as less desirable by Miss Tann almost immediately after being kidnapped. Camellia resists every step of the way. She fights with the workers when ordered around or mistreated. She fights with the older boys who would bully her and her sisters. When she is left behind when her siblings are taken to a “viewing party” so that their charming faces and darling blond curls can make them attractive adoptees, Mr. Riggs rapes Camellia. She lashes out at the workers who then try to force her into a bath. After that, she is taken away, and her siblings never see her again. Rill is told she’s been killed and her body dumped. She lives on in the image of the dragonfly on the bracelets the sisters and later Avery wear. They observe her birthday long after her disappearance.

The youngest of the Foss girls, Fern is also blond and cherubic. Unlike Lark, she is unable to emotionally adapt. Almost as soon as she is taken from her parents, she begins to exhibit clear signs of trauma. She cannot stop bedwetting and cries whenever she is away from her siblings. Rill keeps Fern very close, knowing that she can be beaten for bedwetting and not wanting her to be killed as Camellia was for being too difficult a child. Rill almost escapes to safety while Queenie is still alive but decides she can’t leave without Fern, who she has heard is being returned, having been a bother to her adopted parents. That turns out to be untrue. In fact, Fern’s adopted parents decide to adopt Rill too, realizing the intensity of the bond between them.

Silas is a teenager when he first enters the Floss family’s life. He has been entrusted with the temporary care of the Foss siblings while Queenie is in the hospital. Rill insists she doesn’t need him around, but straightaway she likes his stories of train hopping and living on the rails. She also likes the look of him, even if he is somewhat lean and hungry-looking. She feels an attraction, one that intensifies later when he tries to break her out of the home. He eventually finds her again when she escapes with the help of Arney. Rill loves Silas, she realizes, but when she returns to the Seviers and their safe, suburban life, she has to forget him forever. She can only hope that things turned out well for Silas, who showed her kindness in a time of need.

Avery’s grandmother has recently been placed in a nursing home as her dementia advances. It is painful for Avery to see her grandmother there, as she is close with Grandma Judy, who had a sharp eye and ready opinions on everything. It is unclear how Grandma Judy connects to May until the very end. It is the dragonfly bracelet that brings the women together—May, Grandma Judy, and Avery. In time, Avery discovers that Grandma Judy was a stolen baby, taken from the arms of Queenie and turned over to a prominent, well-connected family. Grandma Judy kept the secret once she learned it, but she sought her sisters out and stayed in touch with them all her life.

Senator Stafford is a prominent, handsome politician battling cancer but trying not to let any sign of weakness show. He depends heavily on his wife and daughters but is stoic and not one to express any emotion. His stoicism does not fade away until the very end of the book when he comes to see the secret life of his mother before him and meets the aunt he never knew, May Crandall.

The true villain in the novel, Miss Tann runs the orphanage. She brokers the children, especially desired blond children like the Foss siblings, to wealthy couples. Later, she demands more money from some, as she does with the Seviers, under the guise of keeping birth grandparents away. She is wantonly cruel and is rumored to have killed Camellia, as she has done with other children that she found too difficult to make money from. When she is out of the children’s home, she presents herself as a pillar of the community, as loving and only concerned for the children’s wellbeing.

Miss Tann’s right-hand woman, Miss Murphy is often intoxicated on the job, especially while berating the children. She runs the day-to-day operation and manages the workers. She makes sure the children are presentable for viewing parties, making them bathe and scrubbing them abusively hard. She doles out punishments and is answerable to Miss Tann.

Miss Tann’s cousin, Mr. Riggs, appears as kindly on first glance. He sneaks into the children’s rooms as they sleep and leaves peppermint candies behind for them. He smiles at them often and tells them he wants to be best friends, but he has an alcohol addiction and a reputation for raping and sexually molesting the children. He rapes Camellia when her siblings are away, and he nearly attacks Rill but is interrupted in the act by Miss Tann. The memory haunts Rill and makes her mistrustful of men.