A Map of Days (miss Peregrine's Peculiar Children, #4)

The fourth novel in the Miss Peregrine's Peculiar Children series opens with 16-year-old Jacob Portman being driven by his parents and uncles to a psychiatric facility in suburban Florida. His family believes he has had a mental health crisis following the death of his grandfather, Abe Portman, who possessed the rare ability to see and fight hollowgast, invisible monsters that prey on peculiars (people born with supernatural abilities). Jacob's friends from the peculiar world appear in the driveway, blocking the car. Their leader, Miss Peregrine, an ymbryne, a woman who can shape-shift into a bird and manipulate time to create protective "loops" (repeating days that shelter peculiars from danger), introduces herself to Jacob's bewildered family while Bronwyn, a girl with superhuman strength, guards the parents in the garage. Jacob learns that the recent destruction of a loop in Devil's Acre reset his friends' internal clocks, allowing them to live in the present without aging forward. He reunites with Emma Bloom, his girlfriend and a fire-wielding peculiar who spent decades as Abe's lover before Jacob was born.

Bronwyn blows Mother Dust's powder, a sleep-inducing substance produced by a peculiar of that name, at Jacob's family to keep them from calling the police. The next day, Jacob attempts to tell his parents about the existence of peculiars and their hidden world. His mother faints. His father, Frank, reveals a partially erased childhood memory of witnessing Abe fight a hollowgast, but Frank rejects Jacob, saying he chose "these people" over his family, and demands that Miss Peregrine erase his memories. She does, planting a suggestion that the parents should vacation in Asia, leaving Jacob the house.

Miss Peregrine creates a "pocket loop" in Jacob's backyard potting shed that connects through Bentham's Panloopticon, a machine in Devil's Acre that links loop doorways across the world, enabling instantaneous travel between Florida and the peculiar world's temporary seat of government. In Devil's Acre, Jacob discovers he is famous; the ymbrynes have fabricated the story that he personally killed Caul, a defeated enemy. Jacob and his friends receive reconstruction assignments, but Jacob is offered only the role of motivational speaker. Miss Cuckoo, the ymbryne overseeing assignments, reveals that America is a fractured territory with no centralized peculiar authority and deep clan conflicts.

While visiting Abe's old house, the group discovers a secret underground bunker. Jacob guesses the lock combination using tygrysku, Polish for "little tiger," the pet name Abe gave him. Inside, a thick operations log reveals that Abe did more than hunt hollowgast: He also rescued uncontacted peculiar children, working with operatives identified by single letters, most frequently "H."

Jacob tracks down H's phone number through a clerk in Devil's Acre. H agrees to meet at the Mel-O-Dee diner, which exists inside a time loop. H tests Jacob by unleashing his tame hollowgast, Horatio; Jacob gains verbal control of the creature, proving he shares Abe's gift. H assigns a preliminary task: Deliver two packages, one marked "Flaming Man" and one marked "Portal," using only a cartoon place mat as a map. If Jacob succeeds, H will assign the real mission: rescuing an endangered uncontacted peculiar in New York City.

Jacob recruits Emma, Millard (an invisible boy), Bronwyn, Enoch (who can reanimate dead things and whose knowledge of British cars proves essential for maintaining Abe's hidden 1979 Aston Martin), and Olive (who is lighter than air). They depart without telling Miss Peregrine. The journey takes them past dangerous peculiars and a gang called the highwaymen who pose as police. A peculiar boy named Paul whom they encounter along the way, a diviner who can locate hidden loop entrances, leads them to Flamingo Manor, a motel loop run by Miss Billie, a demi-ymbryne, one of the lesser practitioners who can maintain loops but cannot create new ones or shape-shift. When the highwaymen harass the motel, Emma, Bronwyn, and Miss Billie's giant poodles dispatch them.

To avoid more highwaymen, the group exits the loop into 1965 and drives through the segregated Deep South, where Paul, who is Black, cannot enter roadside diners. Paul guides them to his home loop in Portal, Georgia, a community set in 1935. Miss Annie, the community's elder, explains that American ymbrynes were systematically eliminated by a secret organization of slaveowners who feared peculiars' power to destabilize slavery, a campaign that continued after the Civil War and left American peculiars fragmented and governed by demi-ymbrynes. Jacob delivers the second package and receives directions to a waypoint in North Carolina.

At a fast-food restaurant that doubles as a peculiar weapons depot, Jacob receives the real mission: Protect and extract an uncontacted peculiar, delivering them to "loop 10044." During the drive to New York, Emma confesses she secretly called a past-looped version of Abe from a payphone in 1965 to say goodbye, admitting that Florida has reopened decades of longing. Unable to compete with her attachment to his grandfather, Jacob tells her they should be "friends," ending their romantic relationship.

In Brooklyn, the group tracks the peculiar to a high school where newspaper reports describe a mysterious blackout and a bathroom explosion. Through Lilly, a partially sighted musician and Noor's close friend, they locate Noor Pradesh, a foster child who can absorb, store, and release light as a devastating weapon. Noor recounts how mysterious operatives began hunting her after her peculiarity manifested. H calls Jacob and orders him to abort, but Jacob ignores the command.

Helicopter-borne attackers storm Noor's hiding place. During the escape, Bronwyn is shot with a tranquilizer dart. The weakened group stumbles into a trap set by Frankie, an independent New York peculiar child with telekinetic powers who drugs them with enchanted food and attempts to auction them to rival New York clan leaders. Emma breaks free, but all three leaders insist they must report the group to Leo Burnham, the feared boss of the East Coast's peculiar underworld.

Leo's enforcers capture the group and transport them into a 1930s New York loop. Leo accuses Abe of kidnapping and murdering children and beats Jacob, sentencing him to execution. Miss Peregrine, alerted by Enoch, arrives and negotiates the group's release, though Noor must remain with Leo.

Back in Devil's Acre, Miss Peregrine reveals that Jacob's mission has seriously damaged secret peace negotiations between America's three major peculiar factions. She assigns punishments, and Jacob's friends refuse to support his continued advocacy for Noor. Emma walks away, warning that his pursuit of Abe's legacy will kill him.

Jacob defies the ymbrynes once more, traveling alone to H's apartment in Manhattan. He finds H mortally wounded and Noor unconscious after H's failed solo rescue attempt. Before dying, H reveals that Noor is "one of the seven whose coming was foretold" by an ancient text called the Apocryphon, prophesied emancipators of peculiardom, and that a secret society of normals is hunting her. H also clarifies that Abe never murdered children, but a shadowy organization called the Society fooled the hollow-hunters seven times into thinking they were rescuing children when they were not, an admission that Abe made consequential mistakes while acting with good intentions. H instructs Jacob to take Noor to V, the last surviving hollow-hunter, who lives "in the big wind."

After H dies, Horatio begins transforming into a wight, a humanoid enemy of peculiars, its tongues withering as its eyes turn blank white, before leaping from the window. Noor awakens and accidentally releases a devastating light blast. Jacob gathers a map, money, and a photograph of a tornado from H's safe and asks Noor to come with him. She says she does not trust him but takes his hand, and the two prepare to flee New York in search of V.