There’s nothing like a car ride with federal agents to make you question your life choices. That was exactly where I found myself the morning of July 18, 2018, winding through the streets of Washington, DC, heading toward an interview with Special Counsel Robert Mueller’s investigators. My trip that morning consisted of riding in two cars, actually—the first took me to a coffee shop that the Department of Justice had randomly selected. This had been the driver’s instructions when I initially slid into the backseat: they had chosen a place unexpectedly, without planning it out or telling anyone beforehand. Then, once we were on our way, he was to radio in our destination. At the coffee shop, the second driver was waiting. Like the first driver, he was wearing a dark suit and dark glasses, but there was a second man with him as well. From the second car—outfitted like the first with tinted windows—I watched as the city’s gleaming monuments, bright and sudden and very white, flashed b...