I think it best that I begin with the end. On March 1, I and dozens of Dan’s friends and fellow activists received a two-page notice that he had been diagnosed with incurable pancreatic cancer and was refusing chemotherapy because the prognosis, even with chemo, was dire. He will be ninety-two in April.

Last November, over a Thanksgiving holiday spent with family in Berkeley, I drove a few miles to visit Dan at the home in neighboring Kensington he has shared for decades with his wife Patricia. My intent was to yack with him for a few hours about our mutual obsession, Vietnam. More than fifty years later, he was still pondering the war as a whole, and I was still trying to understand the My Lai massacre. I arrived at 10 a.m. and we spoke without a break — no water, no coffee, no cookies — until my wife came to fetch me, and to say hello and visit with Dan and Patricia. She left, and I stayed a few more minutes with Dan, who wanted to show me his library of documents that could have gotten him a long prison term. Sometime around 6 p.m. — it was getting dark — Dan walked me to my car, and we continued to chat about the war and what he knew — oh, the things he knew — until I said I had to go and started the car. He then said, as he always did, “You know I love you, Sy.”

So this is a story about a tutelage that began in the summer of 1972, when Dan and I first connected. I have no memory of who called whom, but I was then at the New York Times and Dan had some inside information on White House horrors he wanted me to chase down — stuff that had not been in the Pentagon Papers.