US TOUR 2007, DAY FORTY-NINE:

As expected, the day began with a final breakfast at Cafe Texan. There is, on the wall above the serving counter, a sepia photograph of an old cowboy with abundant whiskers and a huge stetson. It looks like it might have been taken a hundred years ago.

But in fact, that old cowboy still takes his breakfast in the Cafe Texan every day. He looks, if such a thing is possible, even older than his photograph. I took pictures of both. But since I didn't want to invade his privacy (who knows, he might have pulled a six-shooter on me), I snapped him from a distance, so the clarity is not great - but good enough to make the comparison.

We said our farewells to Dick and Michelle, and their delightful four-year-old daughter, Sophia. This has to be the most widely travelled child on earth. She has been to at least fifteen different countries, and counting. They include China, as well as several countries in the continents of Africa and South America. She'll be a real heartbreaker when she grows up. We're all in love with her already - blue eyes, and an ever-ready, constant, and beguiling smile.

A young man with a woollen hat pulled down over his ears took us to the airport. Andrew Link, from Palestine, Texas. He had about him, a military air, lean and fit and alert. "Yessir!" he kept saying to me. It's a long time since anyone addressed me as "sir". That military air might come from his expertise on terrorist bombings in Iraq. Still a student at the College of Criminal Justice, he is participating in a college-sponsored project which tracks terrorist activity around the world. His speciality is Iraq, and he provides the FBI with weekly briefings.

He is just one of a whole generation of law-enforcement students nurtured by Dr. Ward (Dick). They are as fiercely loyal to him as he is to them. To enter into Dick's inner circle, you have to be pretty special. And they are all pretty special kids. "It's like planting flowers and watching them bloom," he told me. "Of course, there are always a few weeds, but for the most part they really flourish. It's hugely rewarding."

And so it was that we took our leave of Houston and Texas, some 500 feet below sea-level, and took a two-and-a-half hour flight to Denver. Colorado, which is 5000 feet above sea level. In addition to losing an hour (we're starting to feel the disorientation of ping-ponging around the time zones), we also felt the loss of oxygen. Breathing is just that little bit harder, everything takes just a little more effort. Of course, one adapts to the change, but I'm not sure we'll be here long enough to fully adjust. On Thursday we head towards the frozen sprawl of Minnesota.

We were met at the airport by our old friends Marilyn Munsterman and Charles Berberich, who have a summer house near where we live in France. But Denver is their home, and their condo has a guest aparment which is to be our home for most of this week.

Although it was cold, the sun was shining, and we were greeted by the sight of the snow-covered Rockies on the western horizon, looking out over the endless dry plains below. As the sun set behind them, we drove out into surburban Denver to the home of Charles and Marilyn's good friends, Fred and Laura, who had laid on dinner for us. Other guests were Harold, who works for the famous Denver bookstore, The Tattered Cover, and his partner John, who works for a publishing house.

Good food, good wine, good company, and by ten we were ready to fall into bed, still in the grip of oxygen starvation, to sleep soundly in the shadows of mountains, anticipating our bookstore event in Boulder on Day Fifty, and another back in Denver on Day Fifty-One.