Each Tuesday during the Twenty Weeks of Buzz, I post about a different one of my twenty novels, giving some bit of insight about the process of writing that particular book. This is week eighteen, so we’re talking about Touchstone, published in 2007.

It’s called intuition, or ESP, or lucky guess. Malcolm Gladwell calls it “rapid cognition.” Robert Heinlein invented the verb, popular to this day among a certain geek contingent, “grok.” Or as Sherlock Holmes said simply (to Watson, who didn’t have it), “You see, but you do not observe.”

I started writing Touchstone a couple of years before Gladwell’s Blink came out but it’s about the same phenomenon: a man glances at a situation and immediately comprehends it, at a person, and understands the whole picture—the person’s past, his current emotional and economic state, his morals, his crimes.

“Cognition” may not be quite the right word, since that implies that an idea and understanding comes to the surface of the mind, even if the thought process itself is too quick to follow. However, often the result is not a clear idea (“This man is a crook.”) but an emotional reaction (“Wow, I’m feeling really uncomfortable.”) Which is the reason why people who teach self-defense to young women stress that if something feels wrong, it probably is.

For a novelist, however, the process behind the feeling that sets a girl’s nerves on end is every bit as interesting as what she does with her awareness. Why do some people seem so remarkably “intuitive” about things? Part of it is training, of course: It’s not too surprising if a lifelong art expert picks out a fake without knowing quite why, or a surgeon knows there’s a problem a moment before the monitors go wild.

But what about a person with a generalized knack, a man who seems to intuit not only forgeries and incipient engine problems but moral decay, unacknowledged passions, and hidden dangers? A man whose skills as a human touchstone would be remarkably useful to all kinds of people? Where would he come from?

Some analytical abilities are a combination of inborn talent and deliberate self-training (Holmes, say, or Conan Doyle’s tutor Joseph Bell.) But if you link the idea of rapid cognition with what is now called PTSD, but was in the 1920s called shell shock, you develop the image of a man whose psychic defenses were stripped from him by trauma. A man with an almost autistic inability to shut out the bombardment of sensory input. A man who self-medicates to dull his senses, who severely limits the demands of social interaction, a man who feels himself walking a constant razor’s edge of sanity.

A man named Bennett Grey.