Two decades later, Dan is a profiler, a psychiatrist who studies the personalities of people incarcerated for murders and sex crimes. Today, he talks to Richard Barber, who has been convicted of the murder of three women, in his office at the prison. When Richard describes a childhood memory of looking at a little girl with long, dark, curly hair, Dan notes to himself that all the women Richard killed had similar hair, which suggests a link between the memory of the little girl and Richard’s crimes. This shows that even a fleeting encounter can have a profound impact on people’s psyches.

However, Dan argues with himself (his method of critical thinking) about the applicability of his hypothesis. Though a random encounter can have a profound impact on a person, it’s difficult to say which encounter shaped their behavior and how. Similarly, though most people incarcerated for terrible crimes have experienced abuse, neglect, poverty, or addiction as children, the reverse isn’t true: The vast majority of people who have grappled with these issues turn out to be decent adults. Back in his office, Dan receives a call from Detective Liam Fleming to come back home to the island on which Dan grew up, as there is bad news about Dan’s father, John.

Though the island of Dan’s childhood is beautiful, his memories of it are complicated. Dan’s mother, Maggie, left the family shortly after the service-station incident. John, bogged down by his responsibilities as a single parent, turned distant. Sarah and Dan drifted apart in their teens. Dan struggled with survivor’s guilt after the Pied Piper was caught, blaming himself for not saving the little boy at the station. Once he went to university, contact with his father became even sparser, though Dan does visit John a few times every year.

Dan meets Fleming at the precinct and recognizes him as a bullying schoolmate. Unlike John, who went into the force to do good, people like Fleming are drawn to powerful positions because of their desire to dominate. Fleming tells Dan that John is missing and that his unlocked car was found at the Reach, the island’s highest point, by Craig Aspinsall, the older man who acts as the island’s unofficial caretaker. Inside the car was a note saying, “Notify my son” (28), leading the police to believe that John may have died by suicide by jumping off the cliff. Fleming wonders if anything was troubling John, but Dan has no idea. As the men wrap up the meeting, Fleming wonders how Dan manages to converse with his clients as if they are humans. Dan replies that he engages with his clients because there is no such thing as monsters. Fleming tells Dan that he’s in a committed relationship with Sarah, information that disturbs Dan more than he lets on. Dan has been single since his last girlfriend, Laura, broke up with him.

Dan goes to John’s log cabin and finds it scrupulously clean, as usual. Dan’s bedroom is tidy and freshly dusted, as if in anticipation of his next visit, and the kitchen and fridge are well stocked with enough food for days. The state of the house puzzles Dan since it suggests that John was planning for the future rather than planning to die by suicide. Dan goes to John’s room next, noticing that his desk is stacked with the crime novels he loves and binders filled with his notes on high-profile unsolved cases that he found online. Since everyday police work on their small island is routine, working on the unsolved cases filled John with a sense of purpose. On the desk is also a blurred photo of John in the woods. Dan doesn’t pay it much attention.

Dan wishes that his father had discussed his troubles with him. Picturing his father’s final, lonely moments, Dan is seized by grief. He goes out onto the deck at the back and sinks to his knees, crying. Later, Dan visits a local pub for a change of scene and, to his surprise, runs into Sarah, who works there as a bartender.

Sarah and Dan sit at a table, and Sarah offers her condolences over his father’s disappearance. Sarah, who worked for an animal charity on the mainland, moved back to the island a year ago to take care of her terminally ill mother. Her mother passed away, but Sarah stayed back to deal with her mother’s debts.

Dan thinks about the last time he saw Sarah, which was at an end-of-high-school party. Everyone had carried something to burn to ashes on the beach, as if to bid goodbye to an old part of life. Most people had carried notes from dreaded classes, detention slips, or old uniforms. Dan brought his worn copy of The Man Made of Smoke so that he could finally move past the terrible encounter at the service station. At the beach, Dan noticed Sarah looking beautiful and happy as she danced with her friends. Dan had wanted to go to her and tell her that he had been in love with her for years but couldn’t find the courage. At the end of the night, he went back home with The Man Made of Smoke still with him.

In the present timeline, Dan congratulates Sarah on pairing up with Fleming. Sarah tells Dan that the relationship isn’t serious, unlike what Fleming may have told him. The reveal pleases Dan. Before they part ways for the night, Dan asks Sarah if his father seemed upset to her the last time she saw him. To his surprise, Sarah replies that John recently stumbled across the body of a woman in the woods.

The narrative shifts to John’s perspective. He is walking along a forest trail when he comes across what initially seems like a pile of charred logs. However, when he looks closer, he realizes that it’s a body, burned beyond recognition. John calls the police station to report the discovery and waits for backup. Even though he’s retired from the force, he resolves to find the person who did such a terrible thing. A crow perched on a branch overhead keeps John company. He doesn’t believe the old stories about birds being messengers between worlds, but at this moment, the crow seems to sense the presence of death.

When Officers Liam Fleming and David Watson turn up, John tells them his hunch that the deceased person is a woman, probably killed somewhere else, and that her remains were left in the woods. Instead of taking John seriously, a territorial Fleming asks John to remove himself immediately from what is now Fleming’s crime scene. John leaves the area, feeling dejected.

John returns home and is tempted to call Dan but is held back by pride. John knows that his son turned out relatively well, but he feels that that’s a testament to Dan’s temperament rather than his upbringing. After Maggie left, John was too depressed and angry to pay Dan the attention he deserved. He wonders if that’s why Dan rarely calls home now. Sometimes, John feels like there is nothing to look forward to in life. If he ended things, no one would miss him.

A few days later, John runs into Sarah during his walk. He knows that Sarah is dating Fleming, a fact he dislikes because of Fleming’s domineering streak, but he keeps his opinions to himself. Sarah tells him that the autopsy of the woman in the woods revealed knife marks on her bones, suggesting that she was tortured before being burned alive. Back at home, John notices an envelope lying in front of the door. Inside is a printed photo of him in the woods on the day he found the dead woman, her blurred remains at his feet.

Back in the present, Dan returns to John’s house, falls asleep, and is woken up by a familiar nightmare in which a small boy stands by his bed, asking for help. Unable to return to sleep, Dan goes to his father’s study. He studies the photo of John in the woods and realizes that it was taken without John’s knowledge since his blurred features appear un-self-conscious. Furthermore, though he can’t make out what is lying at John’s feet, Dan has a feeling that it’s the remains of the dead woman. Dan wonders who took the photo of his father and switches on his computer in search of an answer, but the screen is protected with a password. To get answers about the photo, Dan must follow in his father’s footsteps.

The next morning, Dan heads to the trail where the woman’s body was found. As he approaches the scene, he visualizes his father walking behind him and holds a conversation with him in his mind (Dan’s usual method of critical thinking is to clear his head and put himself in the shoes of his clients). He asks John what his reason was for not reporting the photograph to the police. John replies that he wanted to investigate the case on his own, as he feels that he didn’t do significant work during his time in the force.

When Dan reaches the spot in the woods where the body was found, he places himself in the direction that his father would have been facing when his picture was taken. Dan immediately spots a crag overlooking the woods. He immediately knows that the crag is the vantage point from which John’s photo was taken. Dan climbs up the crag and tries to visualize the killer, a shadowy figure (whom Dan assumes is a man), and asks him why he brought the woman to the woods to be found by someone. The shadowy figure tells Dan that he brought the body to the woods because he wanted to be seen.

On the crag, Dan discovers a camping site and an abandoned tent. Inside the tent is a wallet containing an ID and address belonging to someone called Darren Field. Dan has a feeling that his discoveries aren’t accidental but set up by someone.

In February 1998, 11-year-old James takes a seaside holiday with his mother, excited to see the ocean for the first time in his life. James imagines the beach to be sunny and merry like on television, but the camping site they pull up to is cold and empty. James knows that his mother chose the beach in the off-season because campsite rentals are much cheaper this time of the year. Despite his disappointment, James promises to keep himself in high spirits because he knows that his mother is trying to make the best of things. James hugs his stuffed lion, Barnaby, and smiles. Though he’s too old to carry the stuffed toy around, he does so anyway because Barnaby helps him stay brave and hopeful.

As James helps his mother set up a tent, he wishes that his absent father would return. On Christmas, he wrote a letter to his father, but he isn’t sure if his mother ever sent it. Once the tent is up, James and his mother play Frisbee on the beach for a while. James is briefly happy, but his mother grows tired soon and goes inside the tent to sleep. James walks around on the shore, looking at the ocean and holding Barnaby. After a while, he notices a hypnotic whistling nearby. He turns around and sees a man silhouetted against the sky. Inside his head, Barnaby yells at him to run away, but James is frozen. The man comes close to James, ruffles his hair, and says that nobody sees or cares. James pictures his mother waking up an hour later, finding him gone, and panicking, but it’s already too late.