I hopped off the bottom rang into the Sea of Fertility’s dust, then focused my vision on the object a half mile away.

Peeing my pants was the least of my worries.

Howard lowered my gear rucksack on a synlon rope. I shuffled aside, tripped on a rock, and nearly fell.

I yelped. Falling would kill me if a rock punctured my suit. My coordination sucked after three weightless days, and, even with suit and gear, I only weighed forty pounds.

Howard’s knees wobbled as he backed down the ladder, and I steadied him as he planted his feet in moondust.

“My God. Missus Hibble’s geek is an astronaut.”

So was Missus Wander’s.

I spent ten seconds in mental back-patting while I looked up at the LEM, jumbled boxes papered in gold foil. My escape from the moon depended on discarded Christmas wrap on legs.

I pointed past the LEM’s spider leg. Howard’s mirrored helmet faceplate turned where I pointed.

A hundred yards from us ran the brink of a shallow canyon as wide as a shopping mall. Its edge was strewn with jagged boulders like plowed-up refrigerators. The canyon ended a half mile away. At least, that’s what the distance looked like to me. The moon’s smaller than Earth. The horizon’s closer. They briefed me that the curvature distorts perception. Whatever the distance, my heart pounded.

At the canyon’s end the Projectile rose. We couldn’t know how much of it had burrowed beneath the surface. What we saw was a blue-black dome bigger than a football stadium. Spiral whorls creased its surface like a metallic snail shell.

Howard examined it through binoculars fitted with a rubber hood that fit against his faceplate. “It skidded in here at ten thousand miles an hour, but it seems intact. I was counting on a hull rupture to get you in.”

“In? Inside ?” I pointed at the Projectile.

He lifted the rucksack and strapped it to my back.

Metzger’s voice came from aboard the LEM. “Take care, Jason.”

Howard and I skirted the canyon the Projectile plowed when it skidded in. There was no telling how unstable the disturbed lunar surface could be.

My brief Earthside lessons in moon shuffling at one-sixth my weight clicked in after a hundred fumbling yards. Still, sweat soaked my long Johns in minutes.

Howard clumped and bounded, his hoarse panting roaring in my earpiece. “Flex your knees before you land, Howard. Like jumping rope.”

“I never jumped rope. Worst mistake of my life.”

I looked at the sky. Earth hung before me, blue streaked with gray soot clouds and a quarter million miles away. Was this the worst mistake of my life?

Waiting for Howard took forever. We wound around bus-size boulders just as craggy and uneroded in three billion airless, waterless years as the ones the Projectile had gouged from the substrate days ago. Howard kept stopping and thrusting his faceplate against boulders, muttering about vesicles and rhyolite. On one such detour, he stepped on a smooth spot that turned out to be a dust-filled pothole and sank to his chest. After I hoisted him out, I leashed him to me with synlon cord around our waists so he had to follow my footsteps.

Finally, we stopped and looked up at the derelict fifty yards in front of us. The exposed part of the Projectile rising above us could have been a domed stadium, skinned iridescent blue-black. That it had moved seemed incredible, but spiral scratches scored its flanks. It had been rotating like a passed football when it hit, scraped but barely torn by a ten-thousand-mile-per-hour crash. I whistled.

Howard breathed. “Holy Moly.”

As soon as we got off this rock I was giving Howard expletive lessons.

Something keened in my ears, a repeating whine, high-pitched, then low.

“Howard, I hear sound. But there’s no air to carry the waves.”

He stomped the ground. “The sound’s conducted through rock. The Projectile’s making noise.”

“It was supposed to be dead.”

He turned me, pulled the palm holo from the rucksack on my back, and held it against his suit. “Now we’re recording the sound.”

He dug the spectrometer out of the rucksack and clam-bered over gouged-up rubble toward the Projectile. He tugged me at the end of the cord that connected us like he was a poodle chasing a squirrel.

Pressing the spectrometer’s probe against the Projectile hull, he hummed along with the rhythmic, conducted sound, “Wah-aah, wah-aah.”

While he worked, I looked up. Forty feet above us, just a fraction of the thing’s height, I saw a circular, silver opening.

“Howard!” I pointed. “A maneuvering nozzle! Just like we found in Pittsburgh!”

He stopped humming and backed away from the hull. Standing beside me, he pointed, too. “Better. Look closer.”

I shaded my eyes with a gloved hand held above my visor. A spiral scratch crossed the nozzle and widened into a man-sized gash.

“Weakened hull section ruptured. There’s your way in, Jason.”

“Uh-uh.” I shook my head, the gesture invisible inside my helmet.

He just reached for my rucksack again.

I shook my whole body. “Howard, I hate heights. I hate tight, dark places worse.”

“Jason, if I could climb, I’d do it. It’s the chance of a lifetime.”

“Or the end of a lifetime!”

“But what a way to go!”

Four days ago I was feeling sorry for myself because I couldn’t make a difference. The human race had shipped me a quarter million miles so I could make a difference. I couldn’t say no. I eyed forty feet of slick metal wall that separated me from the goal Howard had chosen and sighed. “I can’t climb that.” Pointing out impossibility wasn’t saying no.

Howard pulled from my rucksack two rubbery, black discs with looped cords on their backs. “Put these on over your gloves.”

“Howard, suction cups work on air-pressure differential. We’re in vacuum.” I was pretty proud I thought of that, even if it was an excuse to wuss.

“These are Attagrips. All-temperature temporary adhesive. You only weigh forty pounds. You’ll climb like a fly on a wall.”

“Oh.” I sighed and pressed one pad to the surface, then the other, forearms quivering. A thumb push released the right-hand pad so I could move it up the wall. Another push refastened the pad. Then I moved the left-hand pad. Howard was right. I scaled the Projectile like a holotoon superhero. Jason Wander, secret identity of Attaboy.

“Howard, what do I do when I get to the opening?”

“First, get inside. Then I’ll tell you what to get out of the rucksack and what to do with it.”

Howard couldn’t plan a coffee break. The other half of his team never finished high school. “Howard, is the human race just making this war up as we go?”

“We do our best work that way.”

The rip’s edge loomed a foot above my helmet visor. I looked down. Howard was only forty feet below, but he looked as small as a cake decoration. I took a deep breath, then another, and levered myself above the brink.

The ripped Projectile skin was two inches thick and the same blue-black color all the way through. I waited as my eyes adjusted to the dark opening. Below the skin, a six-foot lattice of metal as asymmetrical as drool strings made a sandwich filling that separated the outer skin from a second one. The inner skin wasn’t torn. I described it to Howard.

“It’s a pressure hull,” he said.

“What now?”

“Is there a door, a hatch?”

I shook my head.

“Jason? You okay?” Howard’s voice rose an octave.

Any fool who shakes his head at a microphone should be euthanized. “Howard, I don’t see—” Through the dimness I made out indented lines on the inner hull, a parasol pattern. “Wait. There’s something.”

“It’s a repair hatch. You’re in!”

“Forgot my key.”

“Oh.” He paused. “You may not need one. Crawl up to the hatch. It may fail-safe open to motion. So the repairman isn’t stranded in space in an emergency.”