Imagine that your teenage daughter’s been kidnapped. Just when you think things couldn’t get any worse, your child’s abductor passes on the following message: “I’m supposed to tell you that you are not the first and you are not the last. You are in The Chain and this is a process that goes back a long time. I kidnapped your daughter so that my boy will be released. He’s been kidnapped and is being held by a man and woman I don’t know. You must select a target and kidnap one of their loved ones so The Chain will go on.”

That trapping of an ordinary person in an ethical bind from which there’s no escape is the terrifying central plotline of Adrian McKinty’s The Chain (Mulholland, July). PW’s starred review described it as a “no-holds-barred look at how far a parent will go to protect her child.”

McKinty’s prior books have, for over a decade, received accolades. His debut, 2003’s Dead I Well May Be was named the best first crime novel by the American Library Association. Its sequel, The Dead Yard, was one of PW’s best novels of 2006. McKinty’s Sean Duffy series, set during the Troubles in Northern Ireland during the 1980s, one entry from which landed him the 2017 Edgar Award for Best Paperback Original, have been widely lauded. But McKinty says that the Duffy books “weren’t quite breaking through in the way I wanted.” The author’s breakthrough may finally come with this sophisticated and nuanced page-turner that Don Winslow has memorably blurbed as “Jaws for parents.”

McKinty was born in 1968 in Northern Ireland, and the roots of the very American, very 21st-century The Chain can be traced to his childhood there. “I come from Carrickfergus, County Antrim,” he says, “which is where the last witch trial in Ireland took place, and which also had a lot of local superstitions and legends, especially in country areas and especially around Halloween and the Celtic holidays. If you drive near Carrick, you’ll see a lot of trees in the middle of perfectly good fields that farmers have to plow around. They’ll never uproot the tree and, to explain why, they’ll spin some yarn about drainage or shade, but really it’s because it’s a ‘fairy tree.’ There was a lot of stuff like that.”

When McKinty was a fifth grader, a spate of poisonous chain letters were sent to him and his schoolmates. Mrs. Carlisle, his teacher at the time, told the students to bring any such disturbing mail to her so that she could destroy them. McKinty was so worried about the power of what he calls “written enchantments” that for decades he’d check in with his mother to assure himself that Mrs. Carlisle had not suffered a calamity for ending the chains.

The other major inspiration for The Chain’s plot came from something he’d read in 2012 while waiting in a barber shop in Mexico City. The article described the phenomenon of what were called exchange kidnappings: people offering themselves as hostages in exchange for the release of abducted loved ones who were considered more vulnerable. McKinty first made fictional use of such situations in an unfinished short story he started that year, about a mother whose daughter was kidnapped by a Mexican drug cartel, who insisted that to get her back she had to pay a ransom and then pay to have someone else kidnapped to take her daughter’s place—and then that family had to pay the kidnapping forward as she had done.

That kernel of an idea is at the heart of The Chain. The people behind the Chain make frightening use of the amount of information Americans reveal on social media, and so do the Chain’s victims, who must, in the scheme’s brutal and relentless logic, research future victims themselves. The book’s beleaguered heroine, Rachel O’Neill, a single mother and cancer survivor living in Massachusetts, must target someone else’s child whom she can snatch successfully, and who has parents who can pay the ransom and also plan and execute a similar crime. Rachel has a disturbingly easy time learning which children walk home from school or sports practice on their own and discerning their parents’ schedules through Facebook and Instagram posts.

McKinty himself was surprised by such detailed sharing with the wider world. “I’m not on Facebook, but my wife is, and I started looking at her feed one day and at other people’s feeds connected to hers,” he says. “I was horrified about how much information people shared—intimate, personal information about their lives: when they were leaving the house, when they were coming home, where their kids were. There was one person who told the entire world that the back door of her house was broken and jokingly hoped that she wouldn’t get robbed before the locksmith could come on Wednesday. None of her friends told her to delete the post. I did, though, and she did in fact delete it.”

After what he learned, McKinty told his daughters to be a lot more careful about using social media, and he deleted “the location device thing” on Twitter “that tells everyone exactly where you are.”

McKinty hopes that, if The Chain is a success, its readers will seek out his Sean Duffy series. The eighth book, Hang On St. Christopher, is set to publish in 2019, and the series will conclude in 2020 with The Ghosts of Saturday Night (both from Blackstone). But he acknowledges that it’s unlikely they’d sell as many copies as The Chain, which is set in Massachusetts.

“Crime novels set in England, Scotland, or Scandinavia sell well in America because the public seems to be attracted to those places,” McKinty says. “Belfast is a harder sell—especially Belfast during the Troubles. It’s a real shame, too, because I’m so proud of what I tried to do in the Sean Duffy novels: to give a whole glimpse of a warped demimonde, a Ballardian society, on the edge of utter collapse with all its chaos and beauty and ugliness and black humor.”

McKinty’s own personal experiences inform the Duffy books: growing up during the Troubles, he often got a lift to school from a neighbor, who would check that no bombs had been planted under the car each day before they left. McKinty has described his writing about that period as a catharsis for dealing with the PTSD he’d developed as a result of the stress of growing up amid such violence.

Despite The Chain’s very different setting and themes, McKinty says his process for writing it was the same as his process for the other books. “All my books are character-driven stories,” he notes. “You need strong, interesting characters to turn the wheel of the story, so once I had the characters I wanted, the narrative arcs played out the same way.”

McKinty feels that he’s grown as an author since he began the Duffy books. “I’ve learned to be a more compassionate writer,” he says. “I used to be quite afraid of big emotions and moral issues and wasn’t sure how I could handle them, but I suppose experience teaches you how to do that.”

Lenny Picker is a writer living in New York City.