I watched Kira sleep. Soft breathing had turned to light snoring over the years, black hair to gray. She slept deepest in the quiet hours of early morning. There are no secrets when you've lived together thirty years in a nine hundred square foot house.

Almost no secrets.

The sun would rise soon, and I hadn't slept at all. Already the muddy light of the pre-dawn sky was slipping through the bedroom blinds. I stared at Kira's tight gray curls against the ivory pillow and felt an unexpected tightening in my chest. I wanted to kiss her lightly on the forehead, like in the old romances. One last goodbye, violins wailing in the background. But she might wake up, and I couldn't chance it.

Russell followed when I left the bedroom, padding silently behind me. A quick splash of water on my face from the bathroom sink, and I looked up at the mirror, water dripping from my nose. Deep-set eyes beneath dark eyebrows beneath white, bristled hair. Pronounced lines at the corners of my eyes, the edges of my mouth. When had I become so old?

My pack was hidden in the hall closet, behind the vacuum cleaner that Kira used on Tuesdays and the old twelve-string I never played anymore.

Russell watched expectantly while I changed into the clothes I had placed in the side pocket of the pack: thick jeans, a thermal undershirt, the flannel overshirt with the rip in the elbow that Kira had mended for me twice already.

I eased the front door open, pausing each time the hinges protested, listening for sounds from the bedroom. Russell waited patiently through the slow process, head tilted, not making a sound. Smart, quiet, loyal Russell.

That dog, Kira always said, like it was a bad word. That dog is getting hair all over my couch. She had never appreciated Russell. She would be glad that he was gone.

I stroked Russell's velvet head and ushered him out into the icy air.

As I moved to close the door, my wedding band caught the light from the front porch. I pulled the ring from my finger and placed it on the table just inside the door. A small parting gift.

Short, squat houses lined the street. Mine was one in a long row of blank indistinguishable faces, windows like unblinking eyes.

Mine no longer. When the Tourists took me, I would be legally dead. The trust, the savings, my old truck, my cameras, everything would become hers. She would be well taken care of.

The maples planted in the grassy border along the street were growing too large for their confinement, their roots buckling the uniform gray slabs of the sidewalk.

The fog crept up from the river to lie across the road like a tired ghost.

I had never felt so alone. I had never felt so alive.

The Tourists came in gigantic ships. Golden and bullet-shaped, but bristling with flexible antennae like fur, they orbited our sun between Earth and Mars. They sent images and words across the blackness between us.

The Tourists were human-sized, amorphous, soft-spoken. Their heads ballooned and shrank as they spoke; their many eyes wandered this way and that over their soft bodies.

They offered us a deal.

Come tour the universe with us, they said, in Chinese and then in every other human language. They laughed when the scientists asked how they knew our physiology, our languages. When you've toured a while, they said, you will see that there are far stranger beings than you. You are really quite ordinary.

We caught glimpses of those other aliens in the images they sent: beings with limbs like upside-down trees, or bodies like moss, or creatures that moved so fast they were a blur or colors. The Tourists took care of them all.

They sent smaller ships, empty shuttles, to the surface of the Earth. Shuttles to carry us to their touring ships, if we wanted.

What do we give up?

You give up your lives on Earth. While you Tour for fifty years, fifty thousand will pass on Earth. Everyone you know will be dead. Your descendants will have forgotten that you left.

What was in it for them? Nothing. They were Tourists. They wanted company for their journey.

A journey! When I was younger I had yearned to travel the world with just my camera and backpack. But that had never happened. Marriage had trapped me in one city, with a mortgage and a job, and social obligations piling up like the unwanted bills on my desk.

"Do you believe them?" Kira asked one night, glued to the TV like everyone else around the world, as footage of the golden ships played over and over.

"Yes," I answered.

On the screen a golden bullet slid up through a purpling sky. Thousands of people setting out to explore, to watch the birth of stars, to sail the huge, open, waiting universe. I had seen pictures: nebulae and swirling galaxies in an astonishing spectrum of colors, hues I could never seem to capture in my own photography. To set foot on the surfaces of planets in distant galaxies, plateaus overlooking unfathomable depths, gaseous atmospheres as deep and thick as a family secret. Exploration, enlightenment.

My heart fluttered at the sight. Set me free.

Kira turned to me, as if she had heard.

"Why would anyone get on that ship and fly God knows where and leave everything they know behind?"

"Exploring is in our blood," I said. "That's why people came to America. That's why we still cross the North Pole and dive the ocean." The pictures on the screen defied the ordinariness of our living room: mushroom-brown furniture, throw rugs, framed crochet on the walls.

She used to understand. When we were young, we would plan trips together. Someday soon, we told each other, we'll see the Tibetan plateau, the Great Barrier Reef, the Angel Falls of Venezuela. Like love, the dream had faded with time.

"The people who leave will be bored within a week," she said. "And then they'll be stuck and unhappy and wishing they were home."

"For some people, I'm sure that's true."

She gave me an appraising look. I didn't dare say more. I watched the TV steadily.

The houses petered out altogether on the edge of Flagstaff, a half mile from the launch site. The first hint of light at the horizon tinted the clouds a muted yellow, a promise of gold. Already I could see the tip of the shuttle, pointing skyward. It would launch just after sunrise.

More and more cars passed me on the road.

I hefted the pack higher on my back and quickened my pace. Russell padded beside me, claws clicking against asphalt, head low, tired already.

"Hang in there, old boy," I said.

He wheezed a little now, and he couldn't bend low to the ground to sniff out a trail or wiggle sideways, as he had when he was a puppy.

We came to the perimeter of the launch site. A chain-link fence ran alongside the road, abandoned cars parked in the grass next to it. More cars were arriving every moment. Some people leapt out and strode toward the gate in the fence ahead. Others spoke in low, intense voices. Still others just watched.

I joined the line at the gate entrance.

In front of me was a solitary woman, stooped and gray-haired, carrying nothing. In front of her was a family of four, with ten suitcases on a cart, and a small black cat, mewling its displeasure. The two children were bright-eyed, curious, cranky. The cruise ship would be as big as the world they knew. Maybe bigger.

When I signed up for the journey, I told them what I would bring: my pack, my dog. The Tourists said there was plenty of food, that we would be comfortable. Still, some people wanted to bring their entire houses. Maybe they didn't really want to leave.

I took the little Pentax from my coat pocket: f-stop 22 for the glistening shuttle beyond the fence. I didn't know whether I would ever be able to develop the film, but some habits are hard to break.

I hadn't brought a watch, but the rumble in my stomach told me I had missed breakfast. Kira would be up. I thought of her searching the house, of slow realization transforming her face.

My throat tightened at the thought. She would be all right, I told myself. She had her friends, her sisters. They would help her find someone else. Someone settled, someone with no love of the stars, no sense of awe at the beauty of the universe, no unfulfilled need to explore and discover.

The shuttles were scattered across the globe: Africa, South America, Australia, Asia. They would take us, the Tourists said, to the bigger ships, the cruise ships. There would be room enough for farms and towns. We could organize governments and police forces if we wanted.

The world was split. Some said the Tourists wanted us for their own experiments, or maybe for food. Some said we would be pets, like the parrots the Spaniards took home from the Americas after spreading their diseases. We would be the talking birds in lonely cages on a conquistador's balcony. We would die of boredom.

Others pointed out the incredible opportunity offered by the Tourists. We, of all the generations before, had the chance to explore the universe. We would fulfill our true human potential, to reach the stars.

Only one in ten thousand said they would join the Tourists. I couldn't understand why more people didn't want to go. People lived in an invisible, entangling web: parents, children, lovers, jobs, houses. Most lacked the strength to extricate themselves from their own lives.

The day of my decision, I had been in my darkroom. In the dim red light I watched the images emerge from their chemical depths, photos from the outskirts of Flagstaff. Indistinct shapes became small houses with smaller yards, paper bags and empty bottles against chain-link fences, flattened and dying lawns. Houses too weary to lift tilting shutters, to hold onto chipped paint.

No one would buy these pictures. I'd taken my previous photos to every gallery, every art show, every year. Kira said it was a waste of time. She was right.

From outside my small sanctuary, the sound of the television blared away as Kira got her nightly fix. What was the appeal? Eternally happy people with easily solvable problems. She had long ago stopped asking me to watch with her.

One month, the TV announcer droned. One month until the last ship left. Make your decision now.

It made my whole body shake, thinking about how I would feel when they left. I imagined living out the rest of my tired days trapped beneath the Earth's crushing atmosphere. A whole life spent grabbing a free minute here and there to practice my photography, while Kira numbed herself a room and a universe away.

I picked up a photograph using a pair of metal tongs, and there it was in the foreground: a single dandelion, poking impossibly through the tiniest of cracks in the sidewalk, the night's condensation wet and glistening on its hopeful leaves and bulbous head.

Suddenly, the decision to go was easy.

A woman in an orange safety vest, skin red from exposure, checked my ID against her list. I set my pack on the ground and waited.

The wind rattled the chain-link fence. I could hear the murmuring of those in line behind me, the hushed, tense tones.

Finally, the guard smiled at me, blue eyes reflecting the first light of dawn, and nodded me through.

I walked onward.

Sparse grass crunched beneath my boots. The sun loitered just above the horizon, a simmering orange-red globe. The shuttle towered above.

I walked into its long shadow, and the air grew chilly.

At the base of the shuttle was a wide ramp leading up into its interior. I walked up, and found myself in a small circular room where a dozen others waited. An elevator. I held my pack tight against my chest with one hand, my other hand on Russell's collar. A door slid shut, and the elevator began to rise.

A moment later, the door opened onto a larger room filled with seats. The walls and floors were brushed copper, the seats wide and soft, better than first class. This would be our home for the journey to the cruise ship. One entire wall was a window. I walked over to it, Russell beside me.

To the left and right were other viewing rooms, other faces pressed against the hard transparent surfaces, curving out of sight around the ship.

Below I saw the ramp into the ship, and further on, the chain-link fence. A group of protesters huddled beyond the gate, mouths opening and closing in a silent chant.

Already I could feel a vibration through my feet, a rumbling promising a roar. The shuttle would launch on schedule.

Once I had made the decision, the rest was easy.

I signed up in the police station in downtown Flagstaff one afternoon after work. Another man stood at the counter. I tried to give him a friendly smile, but he wouldn't meet my eye. Going on the Tour was nothing to be ashamed of.

The officer behind the counter took my thumbprint, my picture. They made us register to keep track of who left, and to weed out the crazy people, the criminals. But the ones who truly wanted to Tour were the most sane of all.

When I pulled up at home later, Kira was in the front yard. She had spread a blanket on the dirt, and was tugging at the weeds surrounding the base of the small mandarin orange tree she had planted the previous spring.

Her shoulders tensed when I approached, though she didn't turn to look at me.

"It died," she said.

I looked at its thin, peeling branches, at the dead gray buds. I had told her the tree wouldn't last through the winter, but Kira had insisted, saying that the mandarin is especially cold-tolerant.

Kira held a Kleenex to her nose. Was she actually crying over the death of a plant?

I gazed upwards, where the Tourists' ship was visible as a single bright point of light in the sky. Even in midday it was easy to pick out. Soon, I would be up there.

"I'm sorry, Kira," I said. I turned and went into the house to find my pack.

We were lifting, as gentle as a balloon at sunrise. I set my pack at my feet so I could move closer to the window. Already the ground was five hundred feet below, the trees like bits of steel wool scattered across the pale ground. Straight up, toward the quiet black of space.

It was silent within, the whisper of fabric against fabric, an occasional low cough. The young man to my left in fatigues and a thick wool coat pressed his nose to the window, his hands on either side.

The sun's rays streaked the ground in long red arrows. The Earth was so beautiful from above.

The girl next to me held onto her mother's hand and looked up at her with the sudden, desperate realization of a child. "We'll never see our house again?"

The mother placed a hand on her shoulder and pulled her close. "I don't think so."

We'll see much better things, I wanted to say. But there would be time to talk. There would be years and years to talk.

Russell whined.

I opened the top of the pack to take out his breakfast, and there, below the Tupperware container of kibble, was a brown paper bag.

I hadn't packed it.

I withdrew it carefully. The bag was lined and worn from reuse, just like the lunch bags Kira used to pack for me when I went on shoots.

Inside was a small container of applesauce and a plastic bag with a sandwich. Deviled egg, my favorite. I closed the bag again, pressed it to my chest. Thirty years and I thought I had known her. How could she have slept last night, knowing I was leaving? I closed my eyes. I imagined her slipping beneath the comforter, whispering a soft goodnight, knowing her husband would be gone when she woke in the morning.

I felt a tugging on my coat and opened my eyes.

The little girl was pulling on my jacket hem.

"What will you miss the most?" she said. Her mother smiled apologetically at me.

The blues and greens and grays were blurring below, the houses merging into long rows of tan against the darker roads.

What would I miss?

Lightning in the plains, so bright the whole sky sizzles into white-hot life for an instant, and then goes absolutely black. Driving at night in the summer with the window rolled down all the way and the warm rain against my face and the wipers zwipp-zwipping in time to Nina Simone. The throaty warble of a red-winged blackbird in the cattails. The way the fog creeps through the pines by the Colorado River on a cold January morning. The hot, dry smell of the desert. A packed lunch.

How long had she known? The possibilities exploded outward, like the time-lapse film of a flowering orchid, petaled layers concealing velvety depths.

The little girl was staring up at me expectantly.

"Deviled egg," I told her.

She nodded solemnly, satisfied with my answer.

Below, the cities and lakes shrank to silver-streaked pebbles. I placed a hand on the cold transparent surface before me, looking back.

Corie Ralston is a scientist at Lawrence Berkeley National Lab, where she gets to use cool words like "synchrotron" and "anomalous diffraction." When she's not writing, she's reading, playing piano, or attempting to telekinetically control dice in the game of craps. Someday she and her partner Kelly will take down all the Las Vegas casinos.