Caroline had actually met her at one of Mrs. Fletcher’s book signings years before and had been impressed by a remark indicating that Mrs. Fletcher knew what had become of her characters after a book ended. This was intriguing and, as Caroline read after that, she could see what Mrs. Fletcher meant. Authors who knew their characters as people generally wrote more exciting books. And action novels seemed to be better written when the author pictured that action like a film unrolling, rather than directing it on a stage set.

At any rate, Caroline made the suggestion to Charles, and Charles laughed. Married and busy with his own life, the last thing he had time for was writing. But what he hadn’t reckoned with was traveling in his work, and as that travel increased, long nights in hotel rooms also increased in number. Finally boredom sent him to the telephone and he asked Caroline if she’d been serious when she made her suggestion.

Any port in a storm …

By that time, Caroline had almost forgotten even asking the question. But she said yes, what did you have in mind?

Charles answered, “You brought it up, I didn’t.”

There ensued a long period of discussion about what might interest both of us.

Mysteries were popular and selling well. But what kind of mystery? We were both tired of the burnt out Italian/ Irish/whatever cop, drinking too much, overweight, divorced, and about to retire when the case he can’t let go comes along. So psychological suspense seemed to be our best choice. And we couldn’t think of a city both of us really wanted to write about long term—or that someone else wasn’t already using very well.

We wanted something different, something that was interesting enough to keep us guessing and excited. London, Charles said. We’d both been there, we liked the city, we liked the English folks we’d come to know over the years, and it was an excuse to travel. That bug had bitten the entire family at one time or another, and the idea of going back to England to do research appealed. Oddly enough, in the end, we chose not to put Rutledge in London as his patch, seeing far more creative potential in the wide range of villages where class distinctions were blurred and old grudges offered more interesting motives. Even Holmes enjoyed moving out of London.

But—forensic science was taking over police work. Did we really want to spend our time digging into cadavers or swabbing up vomit or looking for threads of carpet in the body hairs of victims? Not really. Mafia, drug runners, terrorists, serial killers—ditto. They weren’t challenging subjects because their motivations are predictable.

The solution regarding forensics was simple: go with an earlier period—one modern enough to be familiar, but still a time frame when forensics was in its infancy. And what was the most traumatic event at that time? World War I.

The next challenge was to consider why ordinary, civilized people sometimes kill. If killing is instinctive, why do we spend millions of dollars training ordinary civilized men to march into battle and shoot the other side? But people do kill without warning, sometimes once, sometimes multiple times. The question then becomes: What is there in a person’s life that makes him or her decide to murder someone? What is the critical factor? And if there is one, how would a policeman solve such a murder? What would he look for? What would make him arrest this person when there were five others with what sounded like equally solid reasons for taking a life?