From the #1 New York Times bestselling master of suspense comes a riveting thriller that probes the deepest terrors of the human psyche—and the ineffable mystery of what truly makes us who we are. Here a brilliant young man finds himself fighting for his very existence in a battle that starts with the most frightening words of all…

At thirty-four, Internet entrepreneur Ryan Perry seemed to have the world in his pocket—until the first troubling symptoms appeared out of nowhere. Within days, he’s diagnosed with incurable cardiomyopathy and finds himself on the waiting list for a heart transplant; it’s his only hope, and it’s dwindling fast. Ryan is about to lose it all…his health, his girlfriend Samantha, and his life.

One year later, Ryan has never felt better. Business is good and he hopes to renew his relationship with Samantha. Then the unmarked gifts begin to appear—a box of Valentine candy hearts, a heart pendant. Most disturbing of all, a graphic heart surgery video and the chilling message: Your heart belongs to me.

In a heartbeat, the medical miracle that gave Ryan a second chance at life is about to become a curse worse than death. For Ryan is being stalked by a mysterious woman who feels entitled to everything he has. She’s the spitting image of the twenty-six-year-old donor of the heart beating steadily in Ryan’s own chest.

And she’s come to take it back.

I have been asked by the secret masters of Amazon how much research into transplant surgery I did before writing Your Heart Belongs to Me. I would like to reveal that, in the interest of accuracy and the accumulation of vivid detail, and because I bring total commitment to my writing, I underwent a heart transplant myself, even though I didn't need one. This would be a lie, however, and people without a sense of humor would write by the hundreds to accuse me of taking a perfectly good heart needed by some patient who really needed it.

To prepare for this novel, I read a few books on the subject of transplants, watched two educational films during which I passed out repeatedly at the sight of blood, and spoke with a few medical specialists in the field--largely to ascertain how they manage not to pass out in surgery every time they expose the pulsing internal organs of a patient.

Ryan Perry, the lead of Your Heart Belongs to Me, is 34, wealthy from the Internet social-networking site that he created, with an ideal life ahead of him. Then he learns he suffers from cardiomyopathy and will die within a year if he does not undergo a heart transplant. The procedure is successful, but a year later he begins to receive gifts--such as a heart-shaped locket--with the message "Your heart belongs to me. I want it back."

Although it might seem to be a ghost story, Your Heart Belongs to Me is something else entirely. In addition to being a thriller with a medical procedure as a key element, it is an unusual love story. Those who have never read my books--we know who you are--might be surprised to learn that more often than not, a love story is part of the mix. In a romantic relationship, we're vulnerable; and when a character in a novel is vulnerable, we are more likely to worry about him or her and to relate more intimately to the story. Furthermore, people in love have something precious to lose, and in their sometimes desperate efforts to hold fast to that love, they reveal themselves more profoundly than they might otherwise.

In the early years of my career--or what we here in Koontzland call "the long slog"--publishers resisted me when I wanted to mix genres. These days, my publisher encourages me to pursue fresh ways of telling stories. Consequently, Your Heart Belongs to Me is a suspense novel and love story with a thread of the supernatural weaving through it, set against a backdrop of medicine and medical mystery, concerning certain issues of ethics that are timeless--and others that are unique to our time. And I promise you that the medical detail is not so graphic that you will pass out.

Q: Your Heart Belongs to Me is very suspenseful but at the same time an affecting love story. How difficult was this to pull off?
A: Well, life is full of suspense and, if we're lucky, it's full of love as well. From minute to minute and day to day, we never know what will happen to us, good or bad, so suspense is the fundamental condition of existence. That doesn't change when we fall in love or when we love a child or a sibling or a great dog. In fact, the more we love, the more we have to lose, which puts a sharper edge on the suspense in life and in Your Heart Belongs to Me. Ryan Perry, the lead of the story, enjoys self-made wealth and good health and the love of a good woman--so when all that starts to slip away from him, it's actually easier for me to move readers to the edge of their seats and keep them there.

Q: Your books are full of details about how things work in the real world--like life in a monastery in Brother Odd, the management of a great Bel Air estate and the intricacies of police work in The Face, Your Heart Belongs to Me is rich with details about medical conditions and heart transplants. Since you don't specialize in one kind of novel, how do you learn about all these different things? Do you engage in a lot of Internet research?
A: I never go on-line. My writing schedule and other obligations keep me busy 18/7. The other six hours, I sleep. I know that I am a potentially obsessive personality and that it's easy to become obsessed with one aspect or another of the Internet, until hours a day are consumed by it. Therefore, I stay away. I do most of my research from books and publications, and by conducting interviews with specialists in whatever fields my story will touch upon. One of my assistants is on-line, and in a pinch, if I can't turn up a fact I need, she can get it for me. As a high-school and college student, I hated research and libraries. I always shamelessly made up the facts in reports that I wrote, and cited nonexistent books by nonexistent writers in my footnotes. And I always got away with it! But as a novelist, I've been surprised to find that I greatly enjoy doing research. I think the difference is--in school, they told me what I had to learn, and I bristled at authority; when I chose the subject, I proved to be an industrious autodidact.

Q: Your hero in Your Heart Belongs to Me, Ryan Perry, is different from your other heroes, like Odd Thomas and Mitchell Rafferty and Tim Carrier. What was it about the story you were telling in Your Heart Belongs to Me that required this change?
A: Most of my heroes come from ordinary occupations--a fry cook, a baker, a mason, a gardener, a bartender--which makes them like many of my friends in real life. But Ryan Perry in Your Heart Belongs to Me has made a couple hundred million from an Internet business. For this story, I needed a hero who, at the opening, has everything: he's wealthy, he has a beautiful girlfriend whom he loves and who loves him, he essentially leads a life of leisure at 34, he's vigorous and handsome and charming.... And then everything that really matters begins to slip away from him. He had to be at the top in order to be at risk of a long fall. As he begins to think that some people in his life are involved in a conspiracy to kill him, he needed to be a man of exceptional resources to pursue that investigation.

Q: Where did the idea for Your Heart Belongs to Me come from?
A: I was on the phone with a friend, talking about a smorgasbord of things, when the subject of heart transplants came up, and he told me something, an anecdote, that astonished me. Before I hung up, I had spun that small fact into a story that I couldn't wait to write. I've already made it clear to him that he gets no royalties! Story ideas have come to me from lines in songs, from a scrap of overheard conversation, from just about everywhere. And sometimes a story pops into my head, and I have no idea what the source of it was. Thank God this keeps happening; otherwise I might have to learn an honest trade like plumbing.

Q: What is next for you? Another Odd Thomas novel?
A: There will be three more Odd Thomas novels, but my book for spring 2009 is not one of them. It's titled The Other Side of the Woods and is in the vein of Life Expectancy. I'm having great fun with it. Even when writing is hard, I always have fun with it. In fact, the harder it is, the more fun it is, because the challenge is what makes the work worthwhile.