No book, of course, should be judged by its cover—but how to categorize a book with two very different ones? Julianne Pachico’s thrilling debut, The Lucky Ones, billed as “a novel” on the front of the American version and, by its English publisher, as a “collection of stories,” manages the feat of making the question irrelevant. Each chapter is, on the surface, a self-contained story with its own narrator, set in a particular time and place. Yet each story haunts the others—echoing, amplifying, complicating them. One character’s fleeting thoughts turn out to concern another’s deepest trauma; shared memories are cast in contradictory lights. And though every taut chapter clarifies a plot whose whole is greater than the sum of its parts, each remains tantalizingly incomplete.

The Lucky Ones, roiling conventions of form and narrative, starts in 2003, backtracks to 1993, and ends in 2013, with plenty of twists and turns in between. The book revolves around a small cast of wealthy girls who met in kindergarten in an international school in Valle del Cauca, Colombia, in the 1990s. Together and apart, they move toward young adulthood as the book progresses. Their parents are “the oil company executives and the mining company investors … the expats from Belgium and members of the school board.” The girls have maids and chauffeurs and bodyguards; kindergarten birthday parties are “epic affairs.” When trouble comes, they expect to be taken away “in a shiny black car with squeaky plastic seats,” rescued by “the international community.” In reality, such conclusions seldom arrive in the Colombia of the 1990s and 2000s, where even (or especially) the border-flaunting, cosmopolitan elites are vulnerable in the face of kidnappings, guerrilla raids, and worse.

The Lucky Ones is no ordinary coming of age novel, and certainly not your standard wealth-porn fare: “Lucky” is a relative term. Growing up, whether the girls like it or not, means coming into uneasy proximity with a conflict that wears on, claiming family and friends and teachers. The vocabulary of war becomes the vocabulary of everyday life—and vice versa. “‘The fish are all assassinated,’” one character remembers saying as a young child, “assuming it was synonymous with dead, thanks to the newspapers and TV.” A lieutenant in a guerrilla group tells his subordinates that “‘The task of Simón Bolívar has yet to be completed,’ like it’s a homework assignment.”

In tackling the challenge of delineating childhood life and brutal war, of untangling the ordinary and the extraordinary, Pachico dares to disorient her readers. She blurs dividing lines between haves and have-nots, Americans and Colombians, guerrilla fighters and good guys, and revels in the messy interconnectedness of characters. Her chapters, all told from different perspectives, are told in different narrative styles as well. She deploys the usual third person and first person, but she also ventures the “we” of a third-grade clique—that’s who disarmingly narrates “Siberian Tiger Park”—and she pulls it off. The alpha girl of the group has been killed in an airplane bombing over Thanksgiving break, and her friends, who aren’t sure how to mourn, or what a plane crash feels like (“how can we ever imagine?”), must now rise to the occasion of directing their own play at recess.

In London we’re orphans. Our faces are permanently smudged with coal dust, our knees rubbed red and raw from clambering up the side of brick buildings. We tap-dance down alleyways, sing the choruses from VHS copies of Oliver! And Mary Poppins, and leave our chimney sweep brushes behind in the library cubbyholes.

Through fantasy, they push forward as a group, the only way they know. Pachico also explores the distances that open up between consciousnesses. The “you” who is the subject of “The Bird Thing” is a maid whose employers we recognize from other chapters but whom she never calls by name. (“You carry the tray out to the swimming pool, where the daughter is splashing and playing Little Mermaid.”) In one chapter, a starving rabbit speaks as “I.” In another, readers learn that the “he” we’re following is quite literally being followed by those doing the telling, who darkly confide that “He doesn’t see us, but we’re watching.”

As the novelist Juan Gabriel Vásquez said last year about his country, Colombian adults and children alike “have grown up in the midst of fear, of anxiety, of the noise of war.” How, then, to make meaning from this noise? Pachico, who grew up in Colombia with a British mother and an American father, seems to have accepted a metaphysical dare to tell a violent story that, for its characters, has no clear beginning or end. In a chapter called “Lemon Pie,” a kidnapped American expat who taught at the international school says of his plight, “It’s hard to know at what point it became What Happened.” He thinks about the question a lot, replaying the series of events that landed him, isolated and delirious, in a remote corner of southern Colombia.

There is a different teacher in the novel who, after his own perilous encounter with a machete-wielding motorcycle gang, hopes he can forget the entire incident. “If he tries hard enough, the memory might just start to fade,” Pachico writes. “It might be like it never happened at all.” He’s not the only one who wills himself to look away, who tries to leave the country or avoid thinking about how things might have been different. But even the characters eager not to remember—and The Lucky Ones includes many of them—can’t seem to escape the past, which stubbornly reasserts itself.

Pachico makes a point of enlisting the reader in the work of recollecting. Details recur, sometimes bearing a hint of the surreal, as clues to guide us onward. Near the beginning, a strange man shows up at the door while a teenage girl is home alone, asking her if she’s ready “to run.” For her, his presence “feels like noticing the shadow of her own half-closed eyelid, something that has always been there and should have been seen at least a thousand times before.” Later, his exact words are repeated (or are they prophesied?) in the maid’s memory of her own mother’s eerie warning years before: “If you’re not careful, they’ll come for you. Knocking on your door, ringing at the bell. ‘I’m here for you,’ they’ll say. ‘Are you ready to run?’” In Pachicho’s pages, What Happened is still happening.

“History is and is not ephemeral; situations and events evaporate, but their moral and intellectual residue does not,” Cynthia Ozick wrote in the introduction to her collection of essays Quarrel and Quandary. In The Lucky Ones, Pachico has shaped that residue into constantly surprising form. History, she recognizes, is only the beginning.