I strolled east into the Barri Gòtic, the gothic quarter. I sensed I had arrived during a tenuous interlude between the departure of the night's last revelers and the morning's first arrivals, and I paused, enjoying the feeling that I was privy to some secret transition. I wandered for a long time, listening to my footfalls on the narrow stone streets, enjoying the aroma of fresh bread and ground coffee, watching as the area's residents gradually emerged from behind the centuries-old façades of scarred but stalwart dwellings to start another day.

After a breakfast of croissants and coffee cortado, I paid a visit to Ganiveteria Roca, a famous cutlery store I'd read about while preparing for the trip. There, among the pewter razors and steel scissors and related items, I selected a Benchmade folder with a three-inch blade. I'd gotten used to carrying a knife in the last year or so, and no longer felt comfortable without something sharp close at hand.

Now properly outfitted, I started my customary systematic exploration of the city. I wouldn't feel at ease here until I had learned how best to blend, or how to escape, should my attempts at blending fail. So I went everywhere, that day and for the five days and nights after, at all times, by all means of transit. I absorbed the layout of the streets and alleys; the location of police stations and security cameras; the rhythms and rituals of pedestrians and tourists and shopkeepers.

But there were so many distractions: the mingled smell of tapas and shawarma among the winding alleyways of El Raval; the sounds of music and laughter echoing in the public squares of Gràcia; the feel of the sea breeze on my face and in my hair on the peaks of Montjuic and Tibidabo. I liked that the locals took for granted morning mass in six-hundred-year-old cathedrals. I liked the contrasts: gothic and modernista; mountains and sea; historical weight and exuberant esprit.