The driver at Heathrow was holding a sign with my name on it in firm, careful script. He was wearing the livery of the Royal Household, and when I said the Queen’s name as a question he presented his credentials as an answer, embossed in gold, and waited.I followed him.

The car was a black Bentley with a license plate bearing only a crown. On the way through London, I watched the city arrange itself outside the window, the Thames and the bridges and the guards in their red tunics, the whole accumulated weight of a place that has been mattering for a very long time and knows it. The driver told me, when I asked carefully, that my grandfather had been regarded in certain circles as a man of unusual discretion. The phrasing had the quality of a classified briefing. I recognized it as such and did not press.

Sir Edmund Fairchild met me in a corridor of Buckingham Palace, his bearing having the same quality as my grandfather’s, the uprightness of men who have spent their lives in proximity to things that require it. He told me my grandfather had commanded a joint American-British operation during the Cold War that had prevented an outcome that Sir Edmund described, with remarkable restraint, as rather disastrous. Few people knew the operation had existed. Fewer still knew what it had cost. My grandfather had been offered a personal commendation by the Queen herself and had declined it.

I asked why.Sir Edmund said he had requested that the recognition be deferred.He gestured to a small leather case on a nearby table. It bore both the Union Jack and the American eagle. Inside was a sealed envelope, a medal, and a letter in my grandfather’s handwriting, the neat military block letters I knew from the birthday cards he sent every year without fail.