The following version of this novel was used to create the guide: Brooks-Dalton, Lily. The Light Pirate. Grand Central Publishing, 2022.

In the small town of Rudder, Florida, a pregnant woman named Frida Lowe struggles to contain her frustration with the life she finds herself in the midst of. Following a disastrous hurricane in San Juan that led to the death of her sister, Frida married an electrical worker named Kirby Lowe, and now lives with him and his two young sons, Flip and Lucas. As a hurricane bears down on Rudder, Frida becomes increasingly agitated with Kirby for not listening to her warnings that they ought to evacuate. Things worsen when Frida enters premature labor while Kirby is attending to a downed wire with his team of electrical workers and her incapacitated state gives Lucas an opportunity to bully Flip into leaving the house in the midst of the storm so they can rob a nearby trailer park. As the hurricane hits in earnest, Frida goes into labor while Flip and Lucas are caught in the gale. Though Lucas is able to seek shelter with a neighbor, Phyllis, Flip is killed by a tree branch as he attempts to flee for home. Frida, meanwhile, gives birth to a baby girl whom she names Wanda in honor of the hurricane that Wanda was born during, then passes away as a result of complications from childbirth.

Several years later, Lucas has grown up and begun working with Kirby. Environmental conditions in Rudder have deteriorated even further; Kirby's electrical team is short-staffed, and mass migrations have begun to occur as sea levels have risen such that many coastal suburbs have flooded. Wanda is largely shunned by her classmates, who distrust her thanks to her association with the hurricane that inaugurated the extreme climate change in the region. One day, Wanda disobeys Kirby and goes to visit The Edge, the place where the ocean meets the suburbs; there, several kids, including two siblings named Corey and Brie, mercilessly bully Wanda before she scares them off by creating a mysterious bioluminescence in the water. Kirby scolds Wanda when she comes home and orders her to begin spending time with Phyllis after school so that someone can watch her. Though Wanda initially resents this, she comes to love Phyllis and is fascinated by the scientific field work that Phyllis does. Meanwhile, Lucas secretly attends to college applications; he hopes to leave Rudder so that he can study climate change and learn how to save it.

Another hurricane sweeps through Rudder, and people continue to leave in droves. After some time, Kirby's team stops receiving funding. When Kirby goes to the municipal building to find out why, he is astonished to learn that the entire county is shutting down and his services as an electrical worker will no longer be needed. Lucas successfully gets into school and begins preparing to leave for California, but Kirby is hesitant to follow him, as he still feels attached to Rudder. Wanda, too, is reluctant to leave, as she has become attached to Phyllis and feels at peace with the surrounding environment. A few days after Lucas leaves, the dam at Lake Okeechobee breaks while Kirby and Wanda are out driving. The floodwaters kill Kirby and sweep Wanda away.

Over several intervening years, Wanda manages to find her way back to Phyllis, and the pair settle into a survivalist lifestyle in Phyllis's blue house, which she has spent her life weatherproofing and stocking with victuals in the event of a climate disaster. Lucas briefly manages to visit once, and brings news that the rest of the country has also been plunged into an environmental catastrophe and is unlikely to survive much longer. While Wanda learns more and more from Phyllis about the surrounding swamp, the pair begins to be tracked by Corey and Brie, who are still lingering in the area. One night, Corey and his father launch an attack on the blue house and severely injure Phyllis. Wanda manages to kill both of their assailants, but she and Phyllis determine that the blue house is no longer safe; they pack some supplies and burn the house to the ground before setting up an outdoor camp in a nearby grove of trees. Because of her head injury, Phyllis slowly begins to lose her mental faculties, and eventually dies, leaving Wanda alone.

As Wanda navigates life alone in the swamps, she comes across another woman while getting fresh water. The woman introduces herself as Bird Dog and invites Wanda to come fish with her again. After some time, Bird Dog reveals that she is, in fact, Brie. Wanda is initially skeptical and flees the area, but later tracks Bird Dog back to her small community and realizes that Bird Dog and her people are scavengers, not bandits. Bird Dog invites Wanda on a scavenging trip, and they make peace with their past there, but Wanda still feels unsafe when Bird Dog invites her to go diving. Though Wanda attempts to hide herself from Bird Dog, a hurricane hits the area, and they are forced to shelter under a canoe together; they initiate a romantic relationship. After several decades, Bird Dog and Wanda manage to build a thriving new community in the swamps.