Jacob heads back to the Priest Hole and tells his father about the trashed house, leaving out the part about being alone when he went there. They talk about how Jacob does not yet have a better idea of his grandfather, and his father says he gave up trying to understand him a long time ago. He says Grandpa Portman did not know how to be a father, so he dealt with it by being absent from his son’s life. He also says that Grandpa Portman kept too many secrets, and that he believed he was seeing another woman because of a letter he received that Jacob’s father and aunt found. Jacob insists that his father is wrong about Grandpa Portman, and that he is going to prove it.
Jacob goes to the island’s small museum, hoping to talk to the curator about the history of the abandoned house. He stops to look at the exhibits, and sees a grotesque looking blackened corpse inside one of the cases. The museum curator, Martin Pagett, shows up, and explains that this is the Cairnholm Man, or the Old Man, a 2700-year-old corpse that was found in an archaeological dig on the island. They found his body in the bog.
Jacob asks Martin about the house, and he tells him that all the people who lived in the house died a long time ago in the war in a German air raid. Jacob insists that that cannot be right, since the letter from Miss Peregrine was dated much later than that. Martin takes Jacob to speak with his Uncle Oggie, an 83-year-old man who has lived in the area his whole life.
Uncle Oggie talks about seeing the children from the house come into town sometimes to buy groceries, but remembers that they always kept to themselves. He remembers the exact day when the island was bombed and the house was destroyed—September 3, 1940, the exact date that Grandpa Portman muttered as he was dying. He said there was one survivor, a young man who wandered into town unscathed after the bombing and said he wanted to go to the mainland and join the war. Jacob realizes that was his grandfather. He tells his father what he learned later, and they realize that Grandpa Portman was likely not affectionate with his son and daughter because he was afraid of losing his family a second time.
Jacob wonders if the letter from Miss Peregrine from fifteen years ago was actually from the woman his grandfather was cheating with, disguising her identity. He falls asleep that night and wakes up to a large bird in his room, staring him down, and his father labels it a peregrine falcon. Perturbed but sure it is a coincidence, he makes the decision to head to the abandoned house one more time to search for any information he can find.
He makes it to the house in a downpour of rain, and chooses to go upstairs to explore first. The rooms look almost as if the children had just left them, with forgotten toys lying everywhere, collecting dust. He finds what must have been Miss Peregrine’s room. In it is a locked trunk. He tries many times to open it, and finally decides to push it over the upstairs railing and let gravity do the work. It smashes straight through the floorboards to the basement, and in it he finds dozens of photographs, all very similar to his grandfather’s old photos. He realizes that those photos must have come from this trunk, from this house.
As he is looking at them, he hears a loud crash somewhere above him in the house, and a girl’s voice says softly, “Abe? Is that you?” Afraid and startled, Jacob stares upward through the hole in the basement ceiling and sees six kids staring down at him. He realizes that they are the children from the photographs. He wants to introduce himself, but he cannot find his voice, and the children, scared, scatter.
He chases the girl for a while and tries to tell her that he is Abe’s grandson, but she keeps running to a mound of stones that Jacob recognizes as a cairn, one of the Neolithic tombs for which Cairnholm was named. He follows her inside of it, but cannot find her once he enters. He tries to figure out what just happened, wondering if this was a hallucination, since the kids were supposed to have died a long time ago.
He decides it is time to stop this and go home, so he leaves the cairn, startled to find that there is no rain in sight and the bog is bathed in sunlight. He walks back into town, but realizes that town is different: there are horse carriages instead of tractors, the buzz of diesel generators is gone, and everyone is staring at him. He goes to the Priest Hole, but the people do not recognize him. They believe he is a German spy, and chase him away.
Jacob tries to figure out whether he is in the middle of a psychotic episode when suddenly the girl he was chasing appears, grabbing him and demanding to know who he is. He explains that Abraham Portman was his grandfather, but she does not believe it. He shows her Miss Peregrine’s letter to prove it, but she still denies it and seems to think he is some kind of monster. Jacob sees a calendar and realizes that it is September 3, 1940. He remembers his grandfather telling him “On the other side of the old man’s grave,” and realizes that he was talking about the cairn. He had gone into the cairn and come out in another time. His knees give out and he faints.
He awakes to the girl and another boy having a conversation over him, arguing about who he is. The boy is invisible, and introduces himself as Millard Nullings. He says the girl’s name is Emma. They run back through town with him, and talk about being from a “loop.” They keep accusing Jacob of being a “wight,” but he has no idea what is going on. Emma calls him her prisoner, and tells him to keep quiet as they ride in a wagon out of town.
Up until this point, Jacob has been lost in a wave of confusion, attempting to piece together eclectic, sparse clues that oftentimes contradict one another. It is only in these chapters that the mystery begins to click, and he discovers the cryptic meaning of his grandfather’s last words by literally stumbling into the world Grandpa Portman once inhabited.
Jacob has always looked up to his grandfather as an idol who had overcome so much hardship in life to become a good man. This is why it hurts him to imagine that his father’s accusations of Grandpa Portman cheating on Jacob’s grandmother are true. This would diminish Jacob’s vision of his hero as an honest, trustworthy man, tainting him with secrets, lies, and adultery.
The photographs that repeatedly appear in this book are paradoxical, in that they do not provide Jacob with what photos are meant to provide. A photograph should be a hard, honest depiction of an event, presenting irrefutable evidence and telling an important story. However, Jacob does not trust the photographs he finds, believing them to be manipulated. Rather than helping him solve the mystery of his grandfather’s past, finding the trunk full of Miss Peregrine’s photos leaves him even more confused.
Much of this mistrust occurs because Jacob has been trained to doubt himself and the things he sees and experiences by the people around him. His parents constantly insisted that there was something wrong with him that needed to be fixed, and his therapist, Dr. Golan, managed to convince Jacob himself that this was true and his mind was broken in some way. As a result, he no longer trusts what he sees with his own eyes. He repeatedly believes he is hallucinating as he moves through the world of 1940, doubting his perceptions of what is occurring. This trait is one of Jacob’s primary weaknesses, and it repeatedly impedes his ability to solve the mystery he sets out to solve.
The theme of time is important throughout the entire novel, but begins to come into play especially in these chapters. This novel shatters common perceptions of time as a linear, fixed entity, painting it instead as something fluid. That Jacob can travel back in time to the day the children’s home was bombed suggests that multiple iterations of time can exist at once—however, Jacob has not yet learned how that is possible.
Chapter 5 pivots from the previous set of chapters, which have been slow and predictable as Jacob slowly finds his footing on the island. This chapter is an onslaught of confusion, presenting many new characters and introducing new mysteries to be solved. Readers are meant to feel as perplexed as Jacob as they confront this entirely new situation, and this keeps the pages turning.