Yesterday morning I stepped out my back door and into Portugal. I didn’t realize at first that I was in downtown Lisbon; I only knew that my wooded New Hampshire back yard with its bird feeders and perennial beds had been replaced by a busy street with small European autos buzzing along, pedestrians in loose cotton smocks and blouses, and a row of cafes populated with customers who looked like extras in a Spanish film. As soon as I caught a voice, though, I recognized the particular intonation of Portuguese, and I knew this had to be Lisbon. I stepped back and touched the shingled wall of my house. The illusion, if that was what it was, didn’t fade. Lisbon looked just as it did in various spy movies. Pastel adobe, hilly streets, rooftops descending like stairs to a vivid blue harbor.

Jeanie leaned from the kitchen window. “What’s going on?” she asked.

“I’m in Lisbon, can you see it?” I cried.

“Of course I can. But what’s Lisbon doing in our back yard? I don’t want to let the cats out. They might get lost on another continent.”

Lisbon didn’t need our cats; it already had plenty. Each of the cafes sported several of them lounging underfoot or even on the tables. “The cafes look pleasant. Come outside. Let’s get breakfast.”

“What if we both leave the house and it disappears?” Jeanie asked.

“Throw a rope out the window and we’ll tie ourselves to it,” I said.

“Don’t be silly, we live in New Hampshire. This Lisbon is just a practical joke or a hallucination.” But she came outside and stepped into the cobbled street, making the little cars halt for her. “Come on,” she said. “No point in dawdling.”

We selected a table at the nearest café. We could look across the street and keep an eye on our house, which seemed to float in a haze of sunlight. Our own cats watched from the kitchen window as a large orange café cat climbed into Jeanie’s lap. The waiter arrived, nodding and smiling. “You own that nice house across the street?” he said in clear but heavily accented English.

“Yes, we do,” Jeanie said, “We’ve been here for twenty-two years.”

“I have often wondered who lived there,” he waiter said. ”I’m glad to meet you at last.”

“How long has our house been there?” I asked.

The waiter looked puzzled. “As long as I have worked at this café, at least. Twelve years next month. I always wondered about it because it is the only wooden house on this street.”

Jeanie and I shrugged. We ordered soft-boiled eggs, toast, and coffee. The coffee came in espresso cups. It was even thicker and blacker than Italian espresso. Round slices of toast cradled the eggs, which the waiter had delivered still in their shells. We cracked them onto the toast and ate. “I could get to like Lisbon,” I observed. But I kept an eye on our house to make sure it didn’t fade away. Our cats watched carefully. They seemed as intrigued as we were to find Portugal in our back yard. But what had happened to our perennial beds? Had the weight of this Lisbon street-scene crushed them?

“Nice breakfast,” I said, “but I’ve got to head for work. Do you want to stay awhile? I’m not sure if you should wander out of sight of the house, but it might be fun to do a little shopping here. I’m sure the stores take Visa.”

The waiter brought our check. As we had no Euros, we had to recalculate the total in American dollars. The waiter seemed happy to accept our cash, however. “I wish you a fine day,” he said, “and I hope you will come again. Now every day when I come to work I will look across the street at your house and tell myself, ‘I know the people who live there.’ And look, your cats are smiling at us.”

“Maybe I’ll wander around a little,” said Jeanie. “Who knows if Lisbon will be here tomorrow? I should enjoy it while I can.”

I left her at the table and crossed the street and returned to our house. When I glanced from the kitchen window Jeanie remained seated at the café table. I leaned out the window and waved, and far down the street I caught the blue of the harbor shining.

The front door still opened onto New Hampshire. I didn’t have time to walk around the house and determine exactly where one world folded into another, so I got in my car and drove off.

During a long dull day at the office I called Jeanie several times and each time she answered on the first ring and raved about the delights of Lisbon. “You were right about the shopping. Lots of beautiful things, and the prices reasonable.”

When I got home just after dusk I could hear the bustle of traffic and see the glow of Lisbon’s lights above our roof. I entered the front door and found a litter of shopping bags crammed with new cotton and linen clothes, pottery, dishes, books in several languages, and other odds and ends. The cats milled around my feet, meowing for dinner. I called, “I’m home,” but got no response. “Still in Lisbon?” I asked. Framed in the kitchen window, the busy street glowed and hummed. But as I stepped out the back door the city lights winked out, the traffic noise stifled, and the gloom of a wooded, unlit New Hampshire back yard greeted me. A barred owl tooted, and nighthawks keened overhead. “Jeanie?” I asked the dark. A mouse rustled underfoot. A mosquito lit on my cheek.