The opening sentences of Jeanine Cummins’ “American Dirt” plunge a reader into the action before politically tinged preconceptions can don armor. Standing at the toilet in his abuela’s bathroom, 8-year-old Luca doesn’t immediately recognize the “mild noise” whizzing past him as a bullet. As screams and gunfire erupt outside the open window, his mother Lydia shields him behind a tiled shower wall while assassins murder all 16 relatives at his cousin’s quinceañera, including his father Sebastián. Lydia and Luca cling to the only family they have left: each other.

It’s a throat-grabbing scene worthy of a spy thriller. But “American Dirt” is not a genre novel, though the adrenaline-pumped page-turner does employ certain dramatic conventions. That scene emphatically answers existential questions that will arise by thrusting readers into Lydia and Luca’s traumatized shoes.

Lydia, an independent bookstore owner, has built a stable, loving life with the honorable Sebastián and map-obsessed Luca in their Acapulco home; she has also enjoyed an emotionally intense friendship with a gentlemanly shop customer, Javier. Too late she learns he heads the new cartel that has terrorized Acapulco and ordered the execution of her journalist husband and family. Tracked by Javier’s ubiquitous spies, including officials at the murder scene, Lydia is transformed into a kind of warrior Ma Joad, swallowing rage to protect Luca — and two dangerously beautiful Honduran sisters they befriend — by jumping on freight trains and hiking across the desert to el norte.

“When the idea first occurred to her as she squatted in the shade of the Oficina Central del Registro Civil, it occurred as camouflage: they could disguise themselves as migrants. But now that she’s sitting in this quiet library with her son and their stuffed backpacks, like a thunderclap, Lydia understands that it’s not a disguise at all. She and Luca are actual migrants. That is what they are. And that simple fact, among all the other severe new realities of her life, knocks the breath clean out of her lungs. All her life she’s pitied those poor people. … This is how it happens. … No one can stay in a brutal, bloodstained place.”

Lydia seeks help from Carlos, Sebastian’s college roommate, who operates a Pentecostal missionary program with his Indiana-born wife, but his wife is unwilling to endanger American students in her charge. Cummins compresses religious hypocrisy, cultural dissonance and proprietary grief into one tense exchange: “Are they just drive-by Samaritans?” Carlos asks. “They just want to make pancakes and take selfies with skinny brown children?”

Mother and son are buoyed elsewhere by lifesaving kindness from strangers — priests, a doctor, an asthmatic orphan, a bank teller whose nephew was beheaded — and whisper the names of slaughtered relatives like prayerful incantations. Lydia worries about the employees she abandoned and shadowboxes with grief that leaves her feeling “tatty as a scrap of lace, defined not so much by what she’s made of, but more by the shapes of what’s missing.” Luca, meanwhile, relives nightmarish memories to assuage his guilt for delighting in moments of wonder — festive church lights, riding through the country strapped to a train roof — when his slain father cannot.

Grim scenes of migrants falling off moving trains or being brutalized by federal agents gain import from factual details, and Cummins rachets up suspense with skill and psychologically astute language. But the book’s most penetrating during reflective moments when Lydia second-guesses her choices and ponders daily rituals and comforts such as morning coffee, moisturizer, and air conditioning that helped insulate her from the troubles of “those poor people.” Now they feel like impossible luxuries and though she has more material resources than most, it’s meager protection.

“Lydia is constantly reminded that her education has no purchase here, that she has no access to the kind of information that has real currency on this journey. Among migrants, everyone knows more than she does. How do you find a coyote, make sure he’s reputable, pay for your crossing, all without getting ripped off?”

In the afterword as well as a recent interview with The New York Times, Cummins states she’s uncertain whether she is “the right person to tell this story.” The Maryland native gained insight from experiences with her husband, who was an undocumented immigrant when they married, and stories from her grandmother, a Puerto Rican immigrant; still, Cummins is not from Mexico. How would she respond if she lived somewhere that collapsed around her? Worried that her privilege would blind her to “certain truths,” she interviewed migrants, families, activists, lawyers and others in Mexico and the US over four years while writing the book. That research gives “American Dirt” humane, ripped-from-the-headlines verisimilitude. Additionally, she writes, her 2004 bestseller “A Rip in Heaven: A Memoir of Murder and Its Aftermath,” about the rape and murder of two cousins, made her “more interested in stories about victims than perpetrators”; her depictions of characters are nuanced with great empathy for their sometimes Solomonic choices.

Expectations for “American Dirt,” Cummins’ fourth book, have been high since 2018, when nine publishing houses engaged in a rare bidding war ultimately won by Flatiron Books, and its gritty evocations of migrants — “singular individuals … not one faceless brown mass,” Cummins writes — have provoked some debate about who has the right to tell migrants’ stories. That is an important discussion. Equally worthy is their humanity, and hopefully the book’s fictional scenarios will deepen consideration of the real-life, complex issues driving people to the border. 

Jeanine Cummins discusses and signs “American Dirt” at Vroman’s Bookstore, 695 E. Colorado Blvd., Pasadena, at 7 p.m. Tuesday, Jan. 28; free admission, but those wanting Cummins to sign their book must purchase a copy in-store. Info: (626) 449-5320.,,