Macy describes Splinter Ridge as a vertical 30-foot drop onto a “boneyard” of debris, confirming that attempting to run it means certain death. The group understands their dire situation: If Leo beats them to the portage, he will be waiting to kill them, but if they don’t make it, the river will. Allie dismisses the idea of overpowering Leo, certain that he has a final, meticulous plan. Macy confirms there are no other exits. Another group will be starting down the river two days behind them, but Allie points out that Leo likely left his wire trap in place, which means that if they don’t beat him to the portage and get help, the following group will likely all die too. With no other choice, the group commits to rowing as hard as possible to reach the portage first. Macy estimates that if they keep their pace up, they will reach Splinter Ridge in eight hours, around the time the sun goes down, facing a seemingly inevitable death.

An excerpt from Backcountry River Running: A Primer issues an unequivocal warning about Splinter Ridge. The river there is designated Class VI, a rating that means it is unrunnable by any type of watercraft. The guide asserts that using the portage trail on the left side of the river is not optional.

The group rows with desperate exhaustion, following Macy’s guidance down the river but failing to spot Leo’s raft. As the day wanes, their hope dwindles. The narrator pushes through her physical pain by imagining Parker encouraging her. In the center of the raft, Imani’s condition worsens; she is bleeding again and has seemingly given up. Macy estimates they still have an hour of rowing left. Kaia hears Parker’s voice repeatedly urging her to “Let the paddles do the work” (243). The words initially frustrate her, as they are all rowing as hard as they possibly can. However, when she sees a bird’s shadow pass over Deborah’s paddle and life vest, she has a sudden, inexplicable realization about the phrase’s true meaning. Believing she has discovered a solution, she abruptly tells everyone to stop rowing.

Kaia proposes a plan: When they get close to the portage point, they will stage their gear, life jackets, and paddles in the raft to make it look like they are rowing toward the deadly Splinter Ridge rapids. At the last moment, they will abandon the raft and swim to the portage point, hoping that Leo will watch the raft go over the falls and believe them dead, buying them time to sneak past him on the trail and escape. 

The group debates the idea’s feasibility. Macy states that there is a 99 percent chance it won’t work. She explains that the lookout point where Leo will likely be is very close to the portage trail, meaning he could catch them in less than a minute if he realizes the raft is empty. Despite the low odds, the group agrees that the plan is their best chance. Imani notes that she can’t swim due to her severed arm and severe blood loss, and Allie promises to swim for both of them, revealing that she was a state champion swimmer in high school. Kaia has a sudden moment of clarity, believing she understands a new way to succeed.

Kaia proposes a change to their plan: She will swim behind the raft while the others head for the portage. She argues that by slowing the raft’s approach to the falls and ensuring that it doesn’t drift sideways (which would reveal it to be unmanned) she can buy time for the others to sneak past Leo on the portage trail. Allie, a strong swimmer, insists on joining Kaia in the water, arguing that two people will have more control and can support each other. The group reluctantly agrees and quickly works together, using paddles, life jackets, and their own extra clothing to build six convincing dummies. As the injured Imani and Macy weaken, the team finishes their task just as the raft approaches the point where Leo will be able to see them. Kaia and Allie prepare to slip into the river to begin the deception.

The group puts their desperate plan into motion as dusk falls. Macy, Pam, Deborah, and Imani enter the river to swim toward the portage trail. Before leaving, Macy gives Kaia and Allie final instructions on how to navigate the upcoming bend and when to swim for the trail themselves, warning them that the current will become much stronger as they approach Splinter Ridge falls. Once the four women disappear into the shadows, Kaia and Allie remain in the freezing water, hidden behind the raft. With encouragement from Parker’s voice in her head, Kaia and Allie fight to control the raft against the current. They round the bend, bringing the decoy raft into view of where they believe Leo is waiting, hoping he will be fooled by the ruse.

As they approach the falls, Kaia and Allie struggle to control the raft in the cold water. They spot Leo watching from a rocky overlook, just as they hoped he would be. Kaia receives instructions from Parker’s voice, urging her to hold their position longer despite the powerful current pulling them toward the drop-off. Allie grows increasingly panicked, fearing that they will be swept over the falls before they can swim to shore. As their strength fails and the raft becomes nearly uncontrollable, they draw level with Leo’s position. He appears to be fixated on the raft, unaware of the deception, leaving Kaia and Allie trapped between him and the deadly waterfall.

At the last possible second, Kaia and Allie release the raft, dive underwater, and swim desperately for the canyon wall. Kaia, guided by Parker’s voice, fights the powerful current and narrowly avoids being swept over the precipice. She and Allie reunite, clinging to the rock face in an eddy just yards from the drop. From their hiding spot directly beneath Leo, they watch as the illusion of the dummies begins to fail. The narrator sees that Leo is holding a hunter’s bow. He shoots arrows into the raft and dummies as they plunge over the falls. The complete silence from the raft confirms his suspicion, and he screams in rage upon realizing he has been tricked.

After escaping the river, Kaia and Allie follow Leo along the portage trail. They find him cornering Macy, Pam, Deborah, and Imani, who are trapped between a cliff and the river at the trail’s end. Leo, with his bow drawn, reveals he needs to kill them himself so that people on the true-crime subreddit will know his name—not Kellen Stroop’s—and so his Lifemark group will have the story he wants told. Kaia spots Leo’s escape route, a small inflatable kayak hidden nearby. Leo demands to know where Kaia and Allie are, refusing to believe they died going over the falls. Macy lies, claiming they are dead, but Leo threatens to start shooting the women, aiming first at Imani.

From their hiding spot behind Leo, Kaia and Allie throw rocks at him. Allie’s rock hits Leo squarely in the back of the head, causing him to stumble, but not before he releases his bowstring, shooting Deborah.

After shooting Deborah in the shoulder, an enraged Leo turns on Allie and Kaia, firing his final arrow. Kaia attempts to push Allie aside, but the arrow strikes Allie in the chest, seriously wounding her. As Leo races back down the trail to attack the other women with a knife, Kaia leaves Allie to help them. Pam and Macy have retrieved a kayak but refuse to abandon the others. Guided by Parker’s voice, the narrator yells “Fight Night,” a reference to the night Macy and Gracy defeated “Bryan” in the tour company’s hazing ritual. Macy understands and leaps onto the inflatable kayak, unbalancing it and sending Leo into the water. The three women manage to overpower and drown Leo, though the narrator is cut across the ribs by Leo’s blade during the fight. Grateful for Parker’s lasting presence within her, Kaia joins Pam in the kayak to paddle for help, while Macy returns to the wounded on the shore.

The epigraph is a quote attributed to a fictional book, Life on the Water: A Guide’s Memoir. It states that a river can only be run once, as the person who returns to run the river again is never the same person they were before.

Six months after the river incident, Kaia reflects on her survival and recovery. She recalls how she and Pam successfully reached a gas station to call for help, leading to the rescue of the other four women. All six survivors—Kaia, Pam, Macy, Deborah, Allie, and Imani—are healing and have formed a deep, supportive friendship, communicating daily in a group chat. The event has been labeled the “Camas Creek Copycat” by the media.

Having been reunited with her dog Bambi, Kaia finally brings herself to open a duffel bag belonging to her late husband, Parker. Inside, among his gear, she discovers a waterproof pouch containing his important papers. At the bottom is a letter addressed to her, which he wrote in case of his death. The letter reaffirms his immense love for her, calling her his soulmate and providing her with emotional closure. Embracing the mixture of grief and love, Kaia resolves to continue living fully.