Guy Martin's mission was James Bondian: To fly, drive, eat, sleep, talk, shop, and even ski his way around Europe, assiduously tracking who, in this age of antiterrorist vigilance, knew what about him, when they knew it, and how

"What's up?" I say.

"Nothing." She smiles diplomatically, casting a practiced glance at my photograph, flipping through forty-odd pages of expired entry and exit stamps. In the next four weeks, I'll be on six flights to five countries, which is to say that various parameters of my identity will take serial beatings from governments, banks, airlines, hotels, car rental firms, shops, restaurants, and telephone companies. It would be nice if this document lived up to its full potential.

A traveler leaves an episodic data trail much like that of a deer: He wakes, forages for sustenance, and noses along his track until it's time to tamp down another bed in the undergrowth. My mission was to fly, drive, eat, sleep, and communicate across the Continent as the monitored man. Shards of the digital me would reside in mainframes strewn from Arkansas to the Alps. Who would know what about me? When would they know it? And what would they do with the knowledge?

In March, a few weeks after my return, the worst acts of terror in Europe to date—192 killed and 2,000 wounded in the attack on the Madrid commuter trains—added much momentum to intelligence and data gathering throughout the European Union. At their emergency meeting eight days after Madrid, EU interior ministers announced that their new policy focus would be on intelligence sharing—in other words, on a vast new flow of data.

"Actually, the machine misread your name and came up with a wrong birth date," the ticket agent explains.

My passport has performed for nine years and hundreds of thousands of miles, faithful as an old hunting dog. The printed information on its old-tech machine-readable stripe—my name, date and city of birth, and place of issue—is legible to the human eye. It agrees with the printed information next to my photograph. But something's wrong with the stripe digitally. If this were October 2004, the government-mandated biometric identification chip (encoding a mathematical reduction of my face) embedded into a new U.S. passport would have provided the necessary tick of authentication, both of the document and of me. Unfortunately, with this aged passport, my only biometric proof—namely, my government-ordered mug shot—is affixed to the old, somehow corrupt, paper.

It's not a deal-breaker, but it's interesting, especially here at the start of the show. What will happen in these few seconds before I am—or am not—given a boarding pass has been subject to millions of dollars of research and is still under debate, here and overseas. In the United States, the Transportation Security Administration (TSA) is attempting to plug a huge breach in the border- and travel-security dike that the 9/11 hijackers—most of them U.S. visa holders—brutally exploited. The basic idea is to try to connect terror watch lists and U.S. government databases more directly with the ticket counter, so that a ticket agent, the government's front-line civilian representative, can make a bedrock security judgment as to how a passenger should be screened.