To her, it looked like a harmless piece of coal, about the size of her fist. She remembers passing it to a Chinese secret agent. She remembers later learning about the train, the bridge, the explosion. Sometimes she thinks she has suppressed many wartime memories, but even after almost 70 years, they can creep back.

Betty McIntosh, 96, says that is part of being a spy: the doubts about whether you did the right thing, and hearing about those who died because of what you did, and whether you had alternatives. But it was a war.

Her friend Doris Bohrer would understand, but even so, McIntosh still hasn’t divulged everything about every World War II mission. Even though it turns out that Bohrer, 88, was an operative in the war, too: OSS, then CIA, just like McIntosh.

To most other residents of the retirement community in Northern Virginia, these two elegant, well-coiffed widows, Betty and Doris to everyone, are just part of the anonymous parade of aged men and women who play mixed bridge, talk about the brand-new heart and vascular center down the road, the day’s menu at the dining hall, and their pets....