Back on Earth, work on the rescue mission had moved at a frantic pace. Everything was checked and triple-checked in space, cutting corners was an invitation for sudden death, but still the rescue mission had been dogged by small problems and minor delays, delays that would have been routine for an ordinary mission, but loomed huge against the tight mission deadline.

The scheduling was almost impossibly tight—the mission had been set to launch in four months, not four weeks. Technicians scheduled for vacations volunteered to work overtime, while suppliers who normally took weeks to deliver parts delivered overnight. Final integration for the replacement for Moonshadow, originally to be called Explorer but now hastily re-christened Rescuer, was speeded up, and the transfer vehicle launched to the Space Station months ahead of the original schedule, less than two weeks after the Moonshadow crash. Two shuttle-loads of propellant swiftly followed, and the transfer vehicle was mated to its aeroshell and tested. While the rescue crew practiced possible scenarios on the simulator, the lander, with engines inspected and replaced, was hastily modified to accept a third person on ascent, tested, and then launched to rendezvous with Rescuer. Four weeks after the crash the stack was fueled and ready, the crew briefed, and the trajectory calculated. The crew shuttle launched through heavy fog to join their Rescuer in orbit.

Thirty days after the unexpected signal from the moon had revealed a survivor of the Moonshadow expedition, Rescuer left orbit for the moon.

From the top of the mountain ridge west of the crash site, Commander Stanley passed his searchlight over the wreckage one more time and shook his head in awe. “An amazing job of piloting,” he said. “Looks like she used the TEI motor for braking, and then set it down on the RCS verniers.”

“Incredible,” Tanya Nakora murmured. “Too bad it couldn’t save her.”

The record of Patricia Mulligan’s travels was written in the soil around the wreck. After the rescue team had searched the wreckage, they found the single line of footsteps that led due west, crossed the ridge, and disappeared over the horizon. Stanley put down the binoculars. There was no sign of returning footprints. “Looks like she wanted to see the moon before her air ran out,” he said. Inside his helmet he shook his head slowly. “Wonder how far she got?”

“Could she be alive somehow?” asked Nakora. “She was a pretty ingenious kid.”

“Not ingenious enough to breathe vacuum. Don’t fool yourself—this rescue mission was a political toy from the start. We never had a chance of finding anybody up here still alive.”

“Still, we had to try, didn’t we?”

Stanley shook his head and tapped his helmet. “Hold on a sec, my damn radio’s acting up. I’m picking up some kind of feedback—almost sounds like a voice.”

“I hear it too, Commander. But it doesn’t make any sense.”

The voice was faint in the radio. “Don’t turn off the lights. Please, please, don’t turn off your light . . .”

Stanley turned to Nakora. “Do you. . . ?”

“I hear it, Commander . . . but I don’t believe it.”

Stanley picked up the searchlight and began sweeping the horizon. “Hello? Rescuer calling Astronaut Patricia Mulligan. Where the hell are you?”

The spacesuit had once been pristine white. It was now dirty grey with moondust, only the ragged and bent solar array on the back carefully polished free of debris. The figure in it was nearly as ragged.

After a meal and a wash, she was coherent and ready to explain.

“It was the mountaintop. I climbed the mountaintop to stay in the sunlight, and I just barely got high enough to hear your radios.”

Nakora nodded. “That much we figured out. But the rest—the last month—you really walked all the way around the moon? Eleven thousand kilometers?”

Trish nodded. “It was all I could think of. I figured, about the distance from New York to LA and back—people have walked that and lived. It came to a walking speed of just under ten miles an hour. Farside was the hard part—turned out to be much rougher than nearside. But strange and weirdly beautiful, in places. You wouldn’t believe the things I saw.”

She shook her head, and laughed quietly. “I don’t believe some of the things I saw. The immensity of it—we’ve barely scratched the surface. I’ll be coming back, Commander. I promise you.”

“I’m sure you will,” said Commander Stanley. “I’m sure you will.”

As the ship lifted off the moon, Trish looked out for a last view of the surface. For a moment she thought she saw a lonely figure standing on the surface, waving her goodbye. She didn’t wave back.

She looked again, and there was nothing out there but magnificent desolation.