The String Diaries is a bold debut novel by British writer Stephen Lloyd Jones that began with a very specific image. For years, Lloyd Jones carried with him the image of a desperate woman driving fearfully through the night, trying urgently to protect her young daughter and her wounded husband from some thing out there trying to harm them.

“I didn’t know exactly what it was at that point,” he admits, from his home in Surrey. “I just had this picture where her husband is bleeding and they need somewhere to hide because something terrible is following them. It remained exactly that while I tried to work out the background of what was actually going on. That scene was the snapshot in my head that intrigued me for a very long time.”

In fact, the novel manages to be both fast-paced and extraordinarily complex. The woman at the center of the story is Hannah Wilde, carrying along her bleeding husband and their innocent daughter Leah. But in a deft move, the author weaves together three interconnected tales; in addition to the chase set in the modern day, The String Diaries also visits Oxford in the 1970s, where academic Charles Meredith investigates the mystery surrounding an attractive companion, and Hungary in the late 19^th century, where a villain named Jakab will emerge from a mysterious people called the Hosszú életek.

Lloyd Jones started writing when he was 15 and studied screenwriting in college but in adulthood found his writing curtailed by his job as director of a major advertising firm in London. After his father passed away in 2008, his creative mind started flowing again.

“It became a moment for me to reassess and think about what was important to me,” says the author. “My dad worked for IBM and often traveled to the States and would bring back whatever was the latest craze, so I was reading Stephen King and Dean Koontz. But that was the point where if I didn’t write the book, it was going to slip away. So I wrote it late at night and sometimes at lunchtime in the coffee shop around the corner.”

Though most of the book is well-grounded in a tense version of reality, the Hosszú életek represent a unique threat. Taken from a Hungarian phrase that means “long lives,” these creatures have an extraordinary ability to shape-shift into any form they like—even those we hold most dear.

“There isn’t any basis in Hungarian mythology for the Hosszú életek,” Lloyd Jones admits, settling a question already raised by early readers. “They are an invention. I’ve always been interested in books and films that have an invented mythology to them. When I worked out exactly what threat was following Hannah and her family, I knew it was going to have to be as fleshed out and as credible as possible. With Hungary’s history, it seemed the right sort of place where this kind of mythology might spring up. I always enjoyed vampire tales so it was probably natural that Eastern Europe would come up.”

In order to ferret out evildoers in the novel, Lloyd Jones has dreamed up a clever process called verification to make people prove they are who they say they are.

“I thought for a long time about their abilities but I also wanted to place a cap on those gifts—essentially what they could do and what they could not do,” he explains. “I thought, ‘If you’re in that situation and facing that particular kind of threat for a long time, what might you develop over time in order to protect yourself?’ ”

While the modern sequences are frenetic and the Oxford ones exploratory in the manner of Dan Brown’s novels, the sequences set more than 100 years ago in Hungary serve to flesh out the character of Jakab, who makes for a decidedly frightening adversary.

“I wanted him to be as fully human as possible,” Lloyd Jones says of his villain. “To avoid lots of exposition, it was important to make those moments immediate by showing them as they happen. Understanding an antagonist’s background can make them even scarier, in a way. Someone who is just described as ‘evil’ can be shallow, to a certain extent. I wanted readers to be able to empathize with Jakab’s personality while still being horrified by his actions.”

So even though there is definitely a supernatural element to The String Diaries, the author has worked hard to make his otherworldly subculture one that can be believed.

“I didn’t want to dwell on the physical aspects of the Hosszú életek,” he says. “I didn’t want those abilities to come without a price. Certainly, Jakab’s ability to change costs him dearly, as it does for all of the Hosszú életek. I think any society such as theirs would have both a complex past and a politicized past. A race that lives with that kind of longevity would also suffer a unique sadness that would grow from their condition, I think. There are lots of twists and turns, but there’s an emotional hook, too. I was just trying to write the kind of book that I would enjoy reading.”        

Clayton Moore is a freelance writer, journalist, book critic, and prolific interviewer of other writers. His work appears in numerous newspapers, magazines, websites and other media. He is based in Boulder, Colorado.