The rat-tat-tat of a stun gun filled the van. The hood closed over my head, and the man forced me to my knees. Water doused the cloth, making it harder to breathe. Knuckles landed on my ribs. Then the door opened, and I could hear the street sounds of Los Angeles as we sped along. The captor threatened to throw me out. I was ready for stinging voltage, for anything, when the man whispered, “It’s out of batteries.”

I was a little disappointed. I’m a novelist and former reporter and this was research—a field exercise on how to escape kidnapping and evade pursuers. The company running the exercise, OnPoint Tactical, trains civilians and military personnel how to survive dangerous situations. I knew that the stun gun was coming. I had actually been looking forward to it, hoping the experience would be as realistic and frightening as possible.

My new book is a man-on-the-run thriller through Southern California, and I wanted to know firsthand what that chase would feel like. But at a time when the most closely held government secrets have been leaked to the web, when you can view first-person GoPro footage from conflict zones, when anyone can learn to pick a lock with a simple Google search—why bother with the handcuffs and the hoods on a hot L.A. day?

It was partly because I missed reporting, and it sounded like fun, but primarily because I hoped doing so would make for a better book. Readers can tell and appreciate when an author has done his homework and brought in fresh, real-life particulars for a scene. And since the characters in my novel are special-operations personnel, accuracy was particularly important out of respect to my readers in the military. The specifics, however crucial, are just a small part of why first-person research matters, but there are always subtler, unexpected lessons I pick up along the way that affect what I write at a deeper level. Sometimes, they help me recalibrate my relationship to the work I do. In my search for realism, I had to reconsider the balance between perfect authenticity and the virtues of fiction itself—as a vehicle that lets us escape everyday life.

When I’m writing, safe at home, caught up in the twists and turns and details of plotting, it can be easy for me to lose sight of the core purpose of thrillers: to thrill. Most of us spend our lives seeking out security and comfort, but once we have it, we look to stories to provide us safe doses of danger. It’s an honor to do that job, to channel excitement for readers, and it’s worth testing my limits by spending a few days filled with equal parts exhilaration and dread.

During the two days before the field exercise, my classmates and I learned how to free ourselves from flexcuffs, rope, and duct-tape bindings, run counter-surveillance, and make fake IDs. Those classroom sessions were a spy novelist’s dream, and the most harrowing task awaited me at the end of the course. On our last day, our lead instructor and Marine and Special Forces veterans would be hunting us across the city through a series of checkpoints to test our skills. I’d have to do it all without money or a phone, and if I was caught, they’d handcuff me to a fence or parking meter and leave me there until I found a way to escape—most likely by acquiring a bobby pin from another classmate or a passerby and picking my way out.

The kidnapping kicked off our final exercise on Wednesday morning. Our instructors left us tied up in the back of a van in an empty parking lot, and as we reached for the bobby pins we had hidden in our clothes, I had my first real lesson in the practicalities of being hopped up on adrenaline. Lockpicking is a very precise skill, but my hands were shaking, so my best option was to shim open the cuffs. With every task I better understood the desperation a hunted man would feel. I was looking over my shoulder constantly during a long day filled with dicey moments: hunched over a padlock in Venice Beach with my picks, or fashioning a shank out of fence picket and a shard of broken glass in Santa Monica, hiding the weapon in a plastic grocery bag as a cop walked past. By the end of the training I had sunburn, blisters, plenty of embarrassment, thirst, hunger, and bruises on my wrists from snapping duct tape and trying (and failing) to break flexcuffs against my chest. But I had succeeded. The trackers never caught me.

Of course, I was never in any real danger. It’s a strange privilege, one I sometimes feel guilty about, to spend my time playing make-believe in dangerous worlds without really knowing the pain and sacrifice of those who spend their lives there. There’s a temptation to do research like this and then pretend you’re some kind of badass, but my training had exactly the opposite effect on me. It was humbling to realize that there’s no way I could hack it for a day in many of the military jobs I write about, and I came away deeply grateful to, and in awe of, those who do.

Over the past few years of researching and writing, I’ve gotten to know a few current and former servicemen and women. Those friendships and conversations helped push back against the narrow perceptions I had picked up about soldiers and special-operations personnel from movies and TV—that they’re near-invincible fighting machines who talk in clipped sentences and deliver one-liners while grievously injured. With an all-volunteer military, fewer and fewer Americans know what military service is like day-to-day, or how soldiers balance the physically and psychologically taxing nature of their work with their personal lives.

It took time to truly appreciate that behind the legendary operations and seemingly superhuman professions I read about in my research, there are real, relatable people quietly doing their jobs. One one occasion, I interviewed a retired SEAL Senior Chief about the last acknowledged U.S. operation involving combat swimmers—a storied attack that took place during the invasion of Panama, where divers in stealth scuba gear sank a ship using a backpack of C4 explosive. I was hoping for general information, but it turned out his buddies had performed that mission. He gave me incredible, novel-worthy details: how divers surface out of the water under a sentry on a pier, and how revolvers are the most reliable weapons to carry when swimming through a silty, polluted harbor.

It was only once I understood that these are flesh-and-blood individuals with families, not bulletproof action heroes, that I felt comfortable attempting such a book. The only thing scarier than my survival class was when some of the military personnel I spoke with offered to read my manuscript. It drove me back toward authenticity on every page, out of respect and no small terror of embarrassing myself with any ridiculous action or parroted Hollywood cliches.

I had initially subjected myself to a fake kidnapping and sought out these military experts in order to get as close as possible to strict realism. Yet oddly enough, these people were the ones who ultimately led me away from that impossible standard. Time and again, they told me to get the details right and strive for authenticity, but that it’s a novel, so it can be, and should be, a little larger than life. They reminded me of what fiction does and why we need it. These guys didn’t want perfect spec-ops verisimilitude. They’d seen that; they lived it. Like the rest of us, they wanted a good story.

It was a relief to think there was something I could offer back to them besides more questions, and to know there was value, even to these men who had seen it all, in the twisting plots and the uncanny protagonists I love to write. What makes fiction work—the compressions of time, space, and character—can make it fail if the logic is forced, or if the machinery shows and tears through the reader’s fragile suspension of disbelief. The thousand little facts that come from good research can mask that one central falsehood: This is just a story. That’s the challenge, the tightrope walk. Earn your fiction with truths—it’s a lesson I’ll keep with me, along with a few bobby pins hidden in my socks.