The book opens with Lisamarie Hill and her parents, Gladys and Al, receiving a life-changing telephone call from the coast guard. Their son Jimmy and his co-worker Josh have gone missing at sea while on a fishing trip, and no trace of their boat has been found. The circumstances of their disappearance are mysterious and there is no sign of the men, alive or dead. The Hills quickly head to Namu to search for Jimmy while Lisamarie stays behind at home with her Aunt Edith. As this is unfolding, Lisa smokes cigarettes and drifts off in various memories of her childhood and adolescence. The memories are often blended together in a non-linear way that makes the book less of a singular narrative than a stitching together of the various pivotal moments that have shaped Lisa's young life.
Through these recollections, we become acquainted with Lisamarie's family. We are taken on their family trip to Monkey Beach where she and Jimmy look for sasquatches and Lisa has one of her first paranormal encounters. We are introduced to Uncle Mick, an especially significant presence in Lisa's life. The goofy yet trouble Mick serves as Lisa's frequent babysitter and inspires Lisa through his goofy, fun-loving ways. He has his own set of troubles, often drinking alcohol and having emotional outbursts. We also meet other family members such as the perpetually drunk Aunt Trudy and her scrawny daughter Tab. And then there is Ma-ma-oo, Lisa's grandmother, who is still very much connected to Haisla ways. The tension between the Western culture, such as Mick's obsession with Elvis Presley, and the lost Haisla tradition is something Lisamarie tries to navigate throughout the book.
Jimmy's disappearance prompts Lisa to think more about him than usual, remembering how they would swim together at the beach and the town pool, where Jimmy eventually honed his abilities and became a competitive swimmer. When they are younger, they play together all the time. However as Lisa becomes more and more of a social outcast and Jimmy an athlete and top student, the two grow apart.
Lisa recalls childhood memories of different supernatural sightings and paints the story of how she gradually became aware of her special "gift"; one that distinguishes her from other children. For instance, she is visited by a little man with red hair each time before a tragedy hits her family. As she grows older, Lisa does not know entirely how to see this little man; sometimes he lacks to provide real comfort. When she tells her grandmother about the little man while out cultivating medicinal plants, Ma-ma-oo tells her that this is a tree spirit who is a guide, but not such a reliable one. Lisa also learns that these spiritual abilities run on her mother's side of the family. Lisa's mother has chosen to suppress her gifts in order to better fit in to the modern way of living.
Lisa's dreams also play a large role in the novel as premonitions of the future that she does not quite know how to harness for good. For example, right before Jimmy goes missing, she has a dream that her brother is on Monkey Beach. Lisa's reminiscing is interrupted from a telephone call from her parents; an empty life raft has been found on the Namu coast. Lisa now urgently feels she must go meet her parents and help search for her brother, jumping in her father's motor boat and heading down the coast. While in the boat, she continues to go back in memory.
After an appearance from the little man, Uncle Mick dies suddenly while out on the ocean. This scars Lisa, who feels that she should have acted on her premonition and saved him. From this moment forward, she deeply struggles to integrate her spiritual abilities with her waking life, which manifests as her becoming somewhat of a social pariah at school. She falls out with her cousin Erica and finds a new clique of friends in Frank, Pooch, and Cheese—a rowdy group of boys who Lisa much prefers over the superficial girls. When Pooch introduces Lisa to a voodoo spell for contacting the dead, Lisa decides to try it, wanting more than anything to revive communication with her passed uncle.
After she does this spell, strange and disturbing things start to happen in Lisa's life. She receives a strong dream message that indicates Jimmy might be in some sort of danger and so she and her friends try to protect him, although nothing ends up happening to him. Then, Lisa's kitten Alexis mysteriously disappears. She tries to locate her by asking a Ouija board, but she only gets cryptic answers. Valentines Day rolls around and Lisa receives a card that she can tell is from her friend Frank, but she ignores it. Throughout these events, Lisa periodically goes on walks and spends time with her Ma-ma-oo, who helps give her some context for the weird things that happen to her, as she is the only adult who will acknowledge the spirit world.
The little red-haired man continues to appear to Lisa in visions. After one such visit, Ma-ma-oo has a heart attack and almost dies. Shortly after, the little man comes again and the next night she goes to a party and is date-raped by her once friend Cheese. Lisa is infuriated that the little man warns her but does not actually help her avoid these events and feels betrayed, telling him not to return.
Lisa's life seems to be unraveling; the spirit world is intruding upon mundane reality more than ever and she frequently sleepwalks. Her parents take her to the hospital for tests, which show that there is nothing physically wrong with her. One day her parents take Lisa to a therapist, who suggests that Lisa's visions are a result of her grief at losing a loved one. However Lisa has a hard time taking this advice, as she can observe a spirit being attached to the therapist and feeding her suggestions on what to say. Lisa does not know who to trust or reach out to anymore, besides Ma-ma-oo.
Ma-ma-oo suffers a stroke, which for once Lisa is not warned about ahead of time; she suddenly comes to appreciate the little man again. Shortly after this, Lisa receives another sign that someone else she loves is in danger but she chooses to ignore the sign. One day Ma-ma-oo dies in a house fire; the spirits had been right. Lisa is left over $200,000 in her will.
Back in the present day, Lisa arrives at Monkey Beach, a place filled with memories. She flashes back to the 2 years after the death of Ma-ma-oo when she hit rock bottom. She drops out of school and moves to Vancouver and blows her trust fund allowance on drugs and alcohol, entertaining her party friends. Finally, a vision of Tab inspires Lisa to make a change in her life. After running into Frank, she learns their old friend Pooch has committed suicide, and they drive back up to Kitamaat together to attend his funeral. Back in her hometown, Lisa decides to give school and her family life a second chance. While away, Jimmy has dislocated his shoulder and is no longer able to swim, while her parents appear gaunt and depressed. Lisa's return is a welcome change for everyone.
Lisa starts to spend more time with her brother, who has started a relationship with a girl named Karaoke. Lisa has been sobering up and putting in effort to succeed in school. When Karaoke leaves town suddenly, Jimmy is devastated and Lisa takes him on a short trip to Monkey Beach so he can recover.
In the final part of the book, Lisa, in the present day, is inspired to stop at Monkey Beach on her way to Namu. There, she begs the spirits to tell her where her brother is, even drawing her blood as an offering. The book ends on an ambiguous note, with Lisa entering in and out of altered states of consciousness, where she meets some of her passed relatives, including Ma-ma-oo, who warns Lisa that she needs to respect her spiritual abilities and not get herself into dangerous situations, as it is not her time to cross over to the other side just yet.
