Karen Hamilton tells me she had two ambitions: to be an airline attendant and to be a writer. With her debut thriller, The Perfect Girlfriend, publishing in March as Graydon House’s lead title for the season, she’s now checked off both of those boxes. Hamilton’s a Brit who flew 20 years for British Airways, a career that informs the novel, giving her the inspiration for the story as well as the ideal setting.

“I would always change out of my uniform in the airport bathroom as soon as we deplaned, because I have a terrible sense of direction and if I was in uniform, people would always ask me which way to go,” Hamilton says. On one such occasion, while she was transforming into a “civilian,” she had an epiphany about the faces we show to the world and how they relate to who we really are. She says she wondered, “What if a person who represents authority and responsibility is actually a psychotic stalker?”

With that idea in Hamilton’s head, the character of Juliette appeared. Then all she had to do was write the book.

Hamilton left flying in 2013 and now lives outside London with her family. Her third son was born in 2011, but she says it was after the birth of her second son, in 2009, that she began to take her dream of becoming a writer seriously: writing every day, attending literary festivals, taking local classes. “I didn’t really know where to start,” she says of her early writing efforts. “I wrote a really bad first book, tried unsuccessfully to get an agent with a second book, and then signed up for a six-month writing course at Faber Academy [an offshoot of publishing house Faber & Faber] in London.”

Encouraged to experiment, Hamilton ditched the rewrite of that second book and started The Perfect Girlfriend. The class response gave her confidence. She says, “Juliette came alive. I also realized how much I like the dark side of human nature. My first book was happy, and that didn’t work.”

The Perfect Girlfriend is the story of a spurned woman who will stop at nothing to win back her lover, Nate, convinced that he is delusional to have left her in the first place. He’s a pilot, and she goes so far as to train as a member of the cabin crew with the airline he flies for. She secretly cleans his apartment, puts food in his refrigerator, and sleeps in his bed when he’s away. In short, Juliette is your worst nightmare.

Hamilton says she’s always been fascinated with people behind uniforms. “When criminals are discovered, it’s always amazing to me how ordinary they usually are, and an airline crew is perfect for reinvention and anonymity. The crew changes every week. Your nature is not easily revealed—an excellent situation for Juliette to keep her obsession secret.”

But think about being confined in an airplane with a psychopath, 35,000 feet in the air. As Hamilton writes: “The exterior world shrinks to the size of the plane’s interior. A mini world, trapped and cut off from the outside...”

In writing The Perfect Girlfriend, Hamilton had the advantage of behind-the-scenes knowledge of flight attendant life. “People are so curious about what goes on,” she says, noting that she was always peppered with questions: What does the crew eat? Where do they sleep? And of course, the inevitable mile-high-club scenario (seems it’s real). She also did research into sociopaths and read self-help books, imagining how the strong language of “going after what you want” would translate to a disturbed character like Juliette.

The Perfect Girlfriend is co-represented by Sophie Lambert of Conville & Walsh in the U.K. and Hillary Jacobson at ICM in New York (the two agencies have a partnership). Lambert saw a short excerpt and says she was “hooked by Juliette.” She adds, “When Karen sent the finished manuscript, I offered her representation immediately. We worked on it together, and I submitted it widely. Alex Clarke at Wildfire [an imprint of Headline in the U.K.] preempted in a significant six-figure deal. We’ve since sold it in 12 territories.”

Lambert sent it to Jacobson in December 2017, and Jacobson says she was “completely intrigued.” She adds, “Any book that can convince me to root for an unsettling character is something special. I conducted the auction from my childhood bedroom in L.A., thinking, ‘Where am I? High school?’ ”

The fact that The Perfect Girlfriend had already sold in the U.K. and had a great marketing plan attached to it appealed to Jacobson when she went looking for a book to represent. Brittany Lavery at Graydon House, a Harlequin imprint focusing on commercial women’s fiction, bought North American rights, also in a six-figure deal.

“I was looking for dark thrillers and dramatic suspense, and here it was,” Lavery says. She was sick in bed when she read the manuscript over a weekend. “I didn’t know if I was clammy from the flu or that the story was giving me chills,” she recalls. “It was so completely creepy, and I read it in one sitting.”

As for Jacobson, The Perfect Girlfriend is her first adult novel sale. “I was so happy to be looped in,” she says.

“This was a big buy for us,” Lavery tells me. “The imprint launched in September 2017, and this was our first auction. It was unusual, because the end of the year is when things are winding down, not a time when deals happen.”

Lavery is also enthusiastic about a sympathetic unsavory character. “It’s the mark of a strong narrator,” she says. When Jacobson asked if Lavery wanted to do more editing, Lavery told her, “This book is done.”

Sales have been strong in the U.K., where The Perfect Girlfriend was released last April and was #6 on the Sunday Times bestseller list for January 20. In Canada, it was released Dec. 31, 2018, and hit #1 on the Globe and Mail’s January 12 hardcover bestseller list. Hamilton did an early promotional tour in November, and an extensive media campaign and ARC giveaways at regional and national trade shows are planned for the U.S. launch.

Hamilton couldn’t feel luckier, she tells me. It took her nine years to write the book and get an agent. “I was at my son’s Beaver Scout meeting when Sophie’s number came up on my phone. I ran outside to get away from the noise. There I was, sitting in my car, when I got the good news!”