As a reporter for the Washington Post, Dan Zak knows a good story when he spots one. In 2012, an amazing story came across his desk. A trio of anti-nuclear peace activists snuck into and vandalized the Y-12 National Security Complex in Oak Ridge, Tennessee, repository of hundreds of tons of highly enriched uranium and supposedly one of the most secure buildings in the world. The sheer unlikeliness of their intrusion sent shock waves through America’s defense industries. Zak started to explore the story, and, after four years of interviews and research, the result is his first book, Almighty: Courage, Resistance, and Existential Peril in the Nuclear Age.

The activists were affiliated with the Plowshares movement, which has staged these types of confrontational protests since the 1980s. However, they probably don’t fit the average citizen’s image of nuclear protestors. Sister Megan Rice was an 82-year-old Catholic nun who spent 40 years teaching in Africa. Michael Wallis was a Vietnam veteran who’d come to believe his service in war amounted to a war crime. And Greg Boertje-Obed was also a fellow veteran and a soft-spoken house painter. All three reached the Highly Enriched Uranium Materials Facility (HEUMF), the supposedly secure heart of America’s nuclear arsenal. Aided by a security system with dozens of inoperative cameras and guards that were used to ignoring false alarms, the activists used bolt cutters to walk through three layers of fences. Once on site, they spray-painted anti-nuclear graffiti on the outside walls of the HEUMF, doused the walls with several baby bottles’ worth of blood, unfurled a banner, and waited (a relatively long time) to be arrested.

Almighty conveys the scope of the world’s complicated relationship with nuclear weapons. However, the power of Almighty lies in Zak’s nuanced portrayals of the individuals involved. From the trio of activists to Kirk Garland, the first security guard on the scene and in many ways the only person punished for the break-in, Zak renders the characters in vivid detail. I talked with Zak recently about America’s relationship with the only human-made objects that have the power to end humanity.

Were you concerned with nuclear weapons before starting this story? Is it a fear you remember from your childhood?

No, I had no relationship to nuclear weapons before this, beside what I might have learned in a history class about Hiroshima or maybe a little about the Cold War. I was born in 1983. I came of age politically, socially after the end of the Cold War. Nuclear weapons had no salience in my life whatsoever—besides occasionally being a plot point in an action-thriller movie.

The book contains stories of safety hazards, accidents that nearly caused global war, and many instances of radioactive contamination. Did you start to get scared by what you’d learned?

Yeah, what’s been most fascinating about that part of it for me is that we’re dealing with the most powerful and destructive devices ever created by man. And we’ve trusted those devices to a very complicated, somewhat clumsy, and utterly banal structure of bureaucracy. And the contrast between the power of these weapons and the muddledness of the structure and the mainframe we put in place to handle them is kind of scary.

They’re designed, elementally, to be vastly destructive. That’s the scary thing. There’s still over 10,000 of these weapons actively deployed across the planet and many more in reserve and awaiting retirement. We’ve found ways to talk about them in very techno-strategic terms that do not immediately communicate the vastness and horror of what they’re capable of doing. They’re in many ways as ever present as they’ve always been, but they’re less on our radar.

The effects of the weapons, the devastation they can cause, are so abstract that it’s actually hard to think about. Especially when none of them have been used in combat in 70 years. There are fewer and fewer people left on the planet who can testify to the nature of these weapons. I think there’s an immensity to what they can do that’s not easy to confront.

What was it like spending this much time with the protesters? Sister Megan, for one, seems like an amazingly strong person.

Sister Megan is a remarkable woman, whether or not you agree with her. She taught for 40 years in Africa and built schools. Instead of retiring and taking it easy, she decided to devote herself full-time to nuclear activism and broke into one of the most secured facilities in the world at 82. That’s remarkable. That is inspiring, I think, regardless of what you believe.

Not that you’d tell me, but have you heard of an upcoming Plowshares action?

I don’t know if they plan to, but it seems like another one is just a matter of time. These have been happening every few years. Y-12 was the last Plowshares action, and that’s four years ago. They also wouldn’t tell me if they were planning one. This is a very organized and highly regimented version of civil disobedience. Their goal is that the world doesn’t know that one has been planned until all of a sudden one is in the news. But if you look at the papers, back to 1980, one of these happens every several years. So who knows?

I found one of the most affecting parts of the book to be the stories of the thousands of nuclear workers who got sick.

There are two reasons I included those. The first is because of Kirk Garland, the guard who first encountered [the protestors] on the site. He’s one of many members of his family who have worked in nuclear security over the decades. Four of them have died from conditions that any reasonable person would assume were tied to their exposure over many years, and he has been diagnosed with multiple sclerosis. He was someone I thought deserved to be in this book.

Also, when I looked at the history of Rocky Flats [Nuclear Plant outside of Denver], I realized the volume of people who have worked in the nuclear enterprise. This is a group of Americans that I had no awareness of. When I learned how many were sick or had died from exposure in plants or exposure in tests, I felt like it was right and proper to include them in this story. There are 700,000 atomic veterans. That’s a lot of people. We’ve spent $10 trillion on nuclear weapons since the 1940s and a huge number of lives, American and otherwise, to develop, manufacture, and test them. It felt like an area of American history and sacrifice that deserved a telling.

The book mentions hundreds, if not thousands, of cases of illness linked to radiation exposure—either purposeful or accidental. Has safety improved? Are more people getting the help they need?

I would say it’s unresolved. One step forward was an act passed by Congress designed to compensate what they called “energy workers.” If the U.S. government feels there’s evidence that whatever you’re suffering from is related to exposure, then they will compensate you. However, there are plenty of people with illnesses and sickness who have not been compensated, chiefly because the connection to their work could not be substantiated to the satisfaction of the government. This is better than no one getting any kind of compensation. But there is a sense, among atomic veterans, that this is a forgotten sacrifice that has not been justly addressed.

Is there another big story in the works for you? Maybe an idea you’re kicking around?

No, not even one that I’m kicking around. I never thought much about writing a book. And after watching colleagues work on a book, I knew it was a difficult and heartbreaking process that should only be entered into if one feels one needs to do it. You just need to do it no matter what. This was the first and only time I felt that way. I felt like I needed to write this book, and it didn’t matter if it was back-breaking and if no one read it. That just didn’t matter. Until I feel those same feelings again I’m not rushing back into that experience.

Richard Z. Santos is a writer and teacher living in Austin. His features regularly appear in Kirkus Reviews, and his other work has appeared in the Rumpus, the Morning News, the San Antonio Express-News, and many others. He is completing his first novel.