Luna lives on a swamp where the water is dangerous. It wasn't always that way. Luna's grandma recalls when the river flowed clear and was swimmable until the day the earth shook and trees fell forming a dam that created an inky sludge of backwaters. The villagers put their homes on stilts and created swinging bridges as sidewalks to get around and used boats for transportation. Any villagers that accidentally got swamp water in their mouths became infected with a wasting sickness and died three weeks from the day. Rumor is that the swamp is cursed and a creature lives below the waters, but Luna doesn't believe it.
Luna loves to pole through the waters on her boat with her younger, joyful sister Willow. One day the two are having a hey-ho time with Willow laughing hysterically as Luna spins the boat. Out of nowhere the boat dips down into the water and Willow gets the murky swamp water in her mouth. Sure enough, symptoms of the wasting sickness appear and Luna does everything in her power to cure Willow. While the reader knows what pulled the boat down, Luna does not and the reader is not sure why Willow was a target. The answers are slowly revealed and paralleled with two points of view.
Luna's story alternates with Perdita's, a sprite who loves to wander and adores her twin sister, Gia. The magical world of sprites is disappearing as more humans appear and dig metals out of the earth. Most metals poison sprites and they can no longer coexist with the humans so they portal to other worlds. The world of magic and make-believe exists in the vast imaginations of children. As they grow up they lose this to some extent as they gain scientific knowledge and explanations. In this story the adults no longer believe in magic and they can't help cure their sickness because they lack the imagination to realize a sprite lives beneath the waters.
At first Luna embraces science and tries to get a doctor to heal Willow. When the doctor says there is nothing he can do, Luna tries to drain the swamp. She goes through all the steps that others have tried and that have not worked. Sometimes science fails with curing or diagnosing diseases and a loved one dies. Luna faces this dilemma but it doesn't stop her. When she embraces the fact that something magical might be happening then she gets results. Unexpected results. Reading fantasy stories means believing in that which is unbelievable, but that can point to truths in everyday life.
Luna learns the satisfaction of trying to do everything she can and that alone gives her peace at the end. It is not the goal so much as the process that is important. When playing soccer the teams that do the best are the ones that don't think about the score but focus on doing what they can and working together as a unit. The same happens in this book except Luna has to work with her best friend, Berry, and less so with the rest of her family. Her uncle gives her a book with a tip on dealing with magic, but people don't really believe in magic anymore. Her mother is so absorbed in her grief and anger that she cannot see how Luna is hurting or her harshness. Luna's grandma refers to moon charts hoping for a cure. In their own way, the family is trying to deal with the hurt and grief but Luna takes the most action out of everyone. She tries the hardest and that is a message we all need to hear over and over again.
Luna's mother has already lost her husband and the thought of losing another family member has put her over the edge. She spends her days in the chapel and has given up hope. Unlike Luna who feels guilty that Willow got sick on her boat, she takes action while the mother seeks comfort in religion. One poignant line shows the difficulty of grief: "Mama had left early that morning taking her frightened fury up to the chapel where it wouldn't lash out like a bent branch and strike Luna's already bowed back." Paralleled to Mama's grief is Perdita's or Perdy's. She has let sorrow turn her into something ugly. She can't stand to see joy in others so she snuffs it out of their lives.
The heart of the story is the bond between sisters. The alternate story strengthens Luna's as it shows how Gia did everything in her power to create a link between herself and her sister so that she could call her home whenever she was wandering. This metaphor reminded me of the parable of the lost son a bit as Perdy is lost but redeems herself when found again. The powerful bond of families and siblings is another theme. Just talk to a grieving person as they talk about going "home" to see the loved ones that have died before them. Just like Gia and Perdy are separated by worlds, so are humans by death from those they love.
Members of the community didn't leave when the river changed, because it was home where their grandparents and "...great-great grandparents had first taken a felled tree and carved a boat to winnow through the streams." Luna's community came together during the river crisis and they helped each other and cared for each other. They still do. I feel a bit like Perdy. A wanderer. One that uses Skype as my magical locket to see those I love. Home for me will always be where I grew up; where my great-great grandparents first migrated to the United States. But home is changing now. My daughter lives in a different state with my grandson. I've lived in different countries. But the one constant has always been my family and that is ultimately what this story is about - being loved, having a home, and doing your best.