The Surrogate walked past Casey’s window. She watched its shadow slip across the shade, then she stood and zipped up her flight suit. This was the day. No matter what.
The doorbell rang.
It was polite, the Surrogate. It had manners. It rang the doorbell. It said please and thank you. It had saved Casey’s life, twice, and the first time she had been grateful.
Casey bit her lip hard enough to hurt. The pain helped her focus on her mission. Because sometimes she didn’t believe in it. Sometimes she was weak and disloyal to her own kind. That was understandable, considering her own kind, the human race, on Earth at least, was an extinct species. What was there to be loyal to?
The embryos. The cloned embryos in cryostasis.
Twenty-six months ago, Casey and her nine crewmates had watched helplessly from orbit while a plague wiped out humanity with the brutal efficiency of a worldwide tsunami. The final message sent from Washington to all orbiting spacecraft said simply, “Don’t come down.” But Casey and her crew had no choice. Without re-supply vehicles, they couldn’t remain in space. Meanwhile, arguments raged on the Lunar colony, which was self-sustaining. Those in favor of staying put seemed to be winning. Then all communication coming from the Moon ceased.
The polite Surrogate rang the bell again. It claimed to worry about her, like a parent. But it couldn’t really be worried about her.
The Surrogate was a machine, a top-secret military-grade AI, from when there had been both a military and anything secret.
Casey stood in the entry, arms folded, feet planted on the vinyl floor. Military housing, drab and cheap. When she was a child in Virginia, Casey had lived with her mother in a big house with white columns in front. She remembered her mother pulling her down the dappled sidewalk in a red wagon, remembered the sound of the hard rubber wheels rolling on pavement. It was funny how that memory stood out but later ones had folded away into the dark. It was like peering down a long tube to a vision drenched in sunlight.
The knob turned, encountered the lock, turned harder until the lock broke and the door splintered away from the jamb.
The Surrogate had a paint-can head, eyes that glowed blue, and a slot mouth. The sturdy torso contained the power source. A flexible spine, like a length of knuckled bike chain, attached the torso to a pair of ingeniously swiveling hips. The legs were like attenuated cages made from carbon rods.
When Casey and her crewmates descended from orbit in two vehicles, automated defenses had immediately attacked them, destroying one vehicle outright and severely damaging the other. Casey managed a hard landing in the high desert of New Mexico near Tourangeau Air Base. Only Casey survived. Pinned inside the wreckage, her leg broken, she had expected to die of plague. The microbes, however, had all perished as soon as no humans were left to host them, and Casey had returned to consciousness and a world of bright pain in time to see the robot Surrogate peel away a flange of the damaged hull and reach for her.
Now Casey had let the Surrogate break open the door of the house. She hoped the destruction would make her angry at the robot, instead of frightened by what she was planning. She needed the anger.
“You didn’t answer, Casey Stillman,” the Surrogate said. “Our agreement was that you would answer.”
“I know that.” Casey’s voice broke. She wiped her eyes roughly. It was the stupid door, wood splintered and hanging there on bent hinges, like a memory of things unbroken that were now broken forever. Instead of producing anger, it lifted the cover off a deep well of sadness. For months after the crash, she had combed the internet and the airwaves, desperate for contact. But if anyone had survived, they were unable to communicate. During those same months, the Surrogate had nursed Casey, waited on and bonded with her—as it was programmed to do.
The robot fitted the split doorjamb together. “I will repair this.”
“Then I will help you move to a new house.”
“I don’t want a new house.” She stood as straight as she could. “I’m flying out to the Doomsday Vault, and you can’t stop me trying. I want you to lower the shield.”
If the Surrogate could have sighed, this is when it would have done so. “As we’ve discussed,” it said, “the embryos will not have survived.”
“You can’t stop me trying.”
“I have never stopped you. You have stopped yourself. Before this, your mission was the gun.”
“Will you not talk about the gun?”
“It concerns me.”
“You can’t be concerned about anything. You’re a machine.”
“I am an empathic Surrogate.”
“If you won’t lower the force shield, I swear I’ll crash into it on purpose and die. I know you don’t want that.”
Almost a minute passed. From the robot came only a sound like a flywheel flutter, or humming bird wings. “Here is my analysis,” the Surrogate said.
“The embryo clones preserved in cryostasis once represented your desire for restoration. But now they represent your desire to stop living. They are like the gun.”
“You are so full of shit.”
“My casing is filled with many things, but excrement is not among them.”
Casey rolled her eyes. “I wish you wouldn’t try and be funny.”
“Apologies. Our relationship has caused a symbiotic evolution of my algorithms. It is by design.”
“This isn’t a relationship,” Casey said. “And the embryo clones are not like the gun.” After the Surrogate came upon Casey fooling around with a pistol and her soft palate, the robot had gathered all the loose weapons on the base and locked them in the armory.
“They beckon, like the gun, and promise the same conclusion. Leaving the protection of this base for a hopeless goal is irrational. It is suicide.”
“It isn’t, but even if it were, it would be none of your business.”
“It’s wiser, and safer, to await the Moonites.”
Casey snorted. She had long given up on a rescue mission from the Lunar colony, though the Surrogate continued to flog the possibility, probably as a strategy to mollify her. But Casey knew they would never come. The Surrogate referred to that certainty as Casey’s “attitude.”
“I’m going to try,” Casey said, “whether you turn the shield off or not.”
“My algorithms will not allow me to restrain you. But if you are determined, then I will come with you.”
“Otherwise I won’t disable the force shield.”
“I already told you, I’ll fly into it. I’ll gun myself.”
“If you truly want to save the embryos, you will let me accompany you. Otherwise you admit your mission is a gun and not what you claim it is.”
“I don’t have to make deals with you.” Casey pushed past the Surrogate and strode out to the street. She stopped and closed her eyes, took a deep breath.
“Well, come on,” she said.
• • • •
Shattered aircraft hangers gaped like broken shells. Black furrows crisscrossed the runways. Wreckage smeared across the tarmac in rusty debris fields. The plague came and was assumed to be an act of biological warfare. Someone in the US, or China, or India, or Iran, or Russia unleashed the first retaliatory assault. The reactive response spread like the plague had spread. The world became a gun aimed at itself, which kept on firing even after there were no humans left to pull the trigger.
Ironically, in the last days, CDC scientists determined that the plague itself had not been an act of war. Microbes had filtered into the atmosphere, where they thrived, located human hosts, and proliferated throughout the population. Where the plague failed to kill, the weapon response from every country in the world had succeeded. The shield over Tourangeau Airbase should have protected it, as should have the shields over the White House, Norad, and other critical places. All the shields had gone down under cyber attacks as vicious as the hardware ones. The Surrogate, however, had figured out the code to reactivate the one at Tourangeau, and now the AI controlled it.
Some air vehicles at Tourangeau Air Base had gone undamaged. A wasp with a long stinger was painted on the nose of the electric VTOL. Casey hauled herself up to the canopy and claimed the forward seat. The Surrogate installed itself behind her. Casey buckled up and began her pre-flight check. But when she attempted to move the control surfaces, ailerons, rudder, and elevators—her side stick and pedals resisted her. “Are you doing that?”
“I will fly us out,” the Surrogate replied.
Casey craned her head around, awkward in the snug helmet. “You just open the shield, like we agreed.”
“The moment this air vehicle passes beyond the shield it will be attacked by weapons still in terrestrial orbit as well as the automated weapons still operating on the ground. I have downloaded complete specs and will fly.”
Casey wrenched at the control stick. “Let me fly my own goddamn ship.”
The Surrogate went quiet. Hummingbird wings fluttered.
Casey closed her eyes, let her fury subside to the point where she could speak without shouting. “You think you can fly better than I can?”
“I do not doubt your skill. But I can predict the assault and react with greater efficiency.”
Casey tapped her fingers on her thighs. She knew the Surrogate was right. The Surrogate was always right. It was one of the most infuriating things about it (a trait the robot shared with Casey’s mother). Rudimentary AIs directed the orbital and ground-based automated weapons. Some of the weapons were “ours,” some “theirs,” some “who knows.” And yes, it was probably beyond Casey’s skill set to evade them all.
“You’ll give me control once we clear the attack?” Casey said.
“There will be other attacks.”
“You will give me control.” Not a question this time.
“Then let’s go.”
The instrument panel and heads-up display came alive. Powerful GE engines spun up. The ship rose vertically. At two hundred feet, the nose pitched down and they powered towards the invisible shield.
Beyond the shield, buried in a Doomsday Vault under the Sangre de Cristo mountains, lay the frozen embryos cloned from some of the greatest scientists and leaders on Earth, including Casey’s mother. They were the seeds of humanity’s future.
And Casey was the last garden.
They sped toward the shield. Casey blinked sweat out of her eyes. “The shield’s off, right?”
“No need. We can pass through unaffected from this side.”
“What? You never told me you could do that! You mean I could have—No wonder you wanted to come. You tricked me.”
“There will be a bump.”
The ship accelerated to full power, crushing Casey in her seat. If there was a bump, she didn’t feel it. The airframe was already shuddering. And then they were through and pitching steeply upward while rolling left. The sky flashed white and blue with energy bursts. The ship rocked wildly.
“Shoot back!” Casey yelled.
Instead, the Surrogate throttled down and deployed speed-breaks, which threw Casey against her restraints. If the Surrogate hadn’t reacted with inhuman speed and precision, the VTOL would have been destroyed. They skated across the sky, wing tips banked steeply. Then they were clear, rolling right and gaining altitude, finally leveling out.
“Okay,” Casey said, “hand it over.”
“I am adjusting the vector,” the Surrogate said. “Destination in six minutes.”
“Give me control!”
“There will be other attacks.”
“You shouldn’t even be here. You lied to me about the shield.”
Casey seized the side stick and pressed her feet to the rudder pedals, fighting the Surrogate for control. She hadn’t realized the robot could lie. That made it almost human. A warning light flickered, and something streaked up from the desert. The Surrogate wrenched the ship over, but the projectile clipped the starboard wing, and the ship barreled out of control. Sky and Earth swapped relative positions. Casey grasped the stick in a death grip. Despite that, the Surrogate established a semblance of stable, albeit inverted flight, rolled again for straight and level, and compensated for the loss of starboard thrust.
“Casey Stillman, let go, please.”
Casey released her grip and watched the displays. Hydraulic pressure dropped steadily on the starboard wing. The strike had severed a line. Worse, battery levels had plummeted, an emergency reflected in the off-key whine of the big electric turbine on the port side.
The ship wallowed toward the ground.
“We’re going to crash!” Casey’s heart was racing.
“I am managing it.”
The remains of a town passed below them. The VTOL, rocking and swaying under depleted power, traveled another mile. A landing pad came into view. The Surrogate angled them toward it, dumping two hundred feet of altitude before rearing back and engaging sputtering vertical thrust. The ship teetered on the edge. Casey tensed her body for impact. In the next moment the undercarriage absorbed the bone-rattling jolt of touchdown. Casey looked up. They had landed fifty yards short of the pad.
The instrument panel displayed the red lines of overtaxed and underpowered systems, and then the display went dark.
Casey popped the canopy. “Don’t say it.”
“Don’t say what?”
“That if I’d kept my hands off the controls we wouldn’t have been hit.”
The Surrogate reverted to hummingbird wings.
Casey unbuckled her restraints and turned around, kneeling on her seat. The Surrogate’s blank face regarded her. “Damn it. Not saying anything is the same as saying it.”
“I could have avoided the attack, yes.”
“I knew you couldn’t resist rubbing it in.”
She climbed down to inspect the damage. Hydraulic fluid dripped on Casey’s boot. A piece of the starboard wing’s trailing edge was missing, a ragged bite taken by the projectile. If the VTOL had been running on jet fuel instead of electricity, it would have exploded. As it was, shrapnel had penetrated the fuselage and damaged the battery array. Maybe the Surrogate could repair the wing, but without power, they were stranded. “I will effect repairs,” the Surrogate said.
“The repair procedure will render me helpless. So you will get your opportunity to pilot us back to base. You will have to manually deactivate the barrier. I will provide instructions. Don’t do it too soon, or the weapons will gain access ahead of you. Don’t wait too long, or you may misjudge the approach and destroy us.”
“How long will repairs take?”
“Estimated three hours.”
“I’ll be back by then.”
“Don’t go, please.”
From the stowage compartment Casey retrieved a pulse rifle, a sidearm, and a flashlight.
“Without me, your survival is questionable,” the Surrogate said.
“Thanks for the vote of confidence.”
But the robot was already dismantling the starboard aileron assembly.
• • • •
Casey hiked up the steep terrain to the blast-door. She stayed off the road, using the trees for cover. Her boots swished in the undergrowth. She held her rifle at the ready, knowing it wouldn’t do her much good if weapons attacked her. Once upon a time, her mother had given her a tour of the Doomsday Vault. Casey had only gone because it was so rare that her mother invited her anywhere. “You’re so busy with your career,” she told Casey, neatly reversing the situation. Casey hadn’t been the one “too busy” for her mother.
Standing before the cryostasis capsules, Casey’s own lifelong position as a daughter-in-stasis did not fail to ring ironic bells. As an Important Person, one of the world’s top researchers in genetic engineering, Casey’s mother had spent most of Casey’s childhood somewhere outside Casey’s childhood. Maybe that’s why the little-red-wagon memory was so important.
At first glance the blast-door appeared intact, a slab of thick steel recessed under a brow of granite. Casey studied it from the trees. Something wasn’t right. Finally, Casey bit down hard on her lip, burst out of the trees, and ran to the door. Nothing attempted to stop her. In a moment, she understood why. From the trees, she hadn’t seen that the door’s magnetic locks had failed, probably as a result of the cyber attack two years ago. A narrow gap presented itself. She hooked her fingers around the edge, and hauled on the door until the gap widened sufficiently for her to squeeze through.
Inside, daylight fell in dusty shafts from the shattered ceiling.
High above, where Casey had been unable to see it, an explosive discharge had ripped open the mountain. Just as the Surrogate had assured her, the weapons had long ago destroyed the Doomsday Vault. Casey’s hope vanished like the mirage it had always been, something to crawl towards in a desert of regret and loneliness. For years, Casey had imagined the cloned embryos, tiny quick-frozen shrimp sealed in cryogenic capsules, buried deep behind impenetrable walls. She had imagined her mother.
Casey unclipped the flashlight from her belt, found stairs, and descended to the cryo vault. She had to be sure. Twenty minutes later, she was.
The embryos were all dead.
Her mother was dead. Again. Of course, it wouldn’t have been her mother, just her genetic potential, her familiar features. Casey would have nurtured the potential in her own virgin womb, would have raised the child behind the force shield, and perhaps she would even have sat with her and told her a fairy tale about the Moonites coming back to Earth.
Casey sat on an iron beam that had partially melted and crashed down. Alone in the dark, she felt the weight of her life, like the weight of the mountain. What else had she expected? The Surrogate had been right, again. The cryo vault was another gun, a thin excuse for a suicide mission. Casey wiped her eyes and stood up. How could a robot know her better than she knew herself? In symbiosis, its algorithms had deciphered the mystery of Casey’s own secret intentions.
She began climbing stairs.
• • • •
The Surrogate had cannibalized itself to repair the ship. Hollow rods from its legs completed the broken linkages in the starboard aileron assembly. Unused rods and couplings lay in the wing’s shadow, like discarded turkey bones. The hydraulic line had been welded, but what good would that do without fluid in the reservoir?
Using only its arms, the Surrogate had pulled itself back to the cockpit, where it sat bolt upright in the pilot’s seat, strapped in place.
“Okay,” Casey said. “You were right about the cryo vault. Satisfied?”
The Surrogate did not reply.
Casey hauled herself up to the cockpit. The Surrogate had patched a line from its own body and drained itself of fluid, giving the wing reservoir a blood transfusion. A thin cable led from the Surrogate’s chest through a new hole in the firewall to the batteries. Casey toggled the power on. Battery levels jumped to ninety-six percent. But the surrogate was inert. Even the hummingbird was still.
A different emotion supplanted all the others roiling inside Casey, an emotion she had once felt acutely and then spent years suppressing.
“You goddam piece of junk,” she said, not meaning it.
Without the Surrogate, there was only Casey’s voice left in the world.
A tablet device lay on the tandem seat. Words displayed on the screen, instructions on transmitting a number sequence. Casey picked up the tablet, which was the key to unlocking the shield. She climbed into her seat, buckled her restraints, and waited for anger to muscle aside the grief of loneliness; then she spun up the engines, lifted away, and swung towards home base.
The first attack came almost immediately. Projectiles streaked up from the desert. Casey rolled left, rolled right, then plunged for the desert scrub, leveling out at fifty feet. A warning light flashed. Out of the clouds, a glittering swarm came at her.
Casey punched the throttle. The electric power plants whined like things about to burst apart. A burning odor filled the cockpit. The Surrogate rattled and bounced on the cable, the ship violently sucking the last kilowatt from its chest. The base lay dead ahead. So did the shield.
Heat rays crossed her flight path. Casey banked onto her wingtip and veered between them, flying with the skill of unconscious desperation, proving she did want to live. The maneuver drew the attack swarm into the rays. Fireballs burst like red kernels all around her. Casey tapped in the key code and transmitted it to the shield. She squeezed shut her eyes as the VTOL streaked over the border, the force shield rising automatically behind her. Rays, projectiles, and swarms burst spectacularly against it.
On the ground, Casey threw open the canopy. Sweating profusely inside her flight suit, she reached over the seat to unbuckle the robot, but the straps had melted into its frame. She used her knife to cut them away. The Surrogate’s metal body remained searingly hot. Casey ran to the nearest intact hangar and returned with a chain-fall and a rolling cart. She pulled on big silver oven-mitt-looking asbestos gloves and used the chain-fall to hoist the Surrogate out of the cockpit and lower it onto the cart.
• • • •
Restoring the Surrogate’s mobility proved impossible. Casey had left the turkey bone parts behind, and she wasn’t a mechanic, anyway. Replenishing the robot’s power seemed at least worth a try. Casey rolled the Surrogate to the fusion generator building, which powered the force shield and everything else on the base. She rigged a connection between the generator and the Surrogate, and then she waited. After three days the Surrogate showed no signs of life, or whatever it was that animated the AI. After a week she stopped checking on it.
Without the Surrogate’s voice, the base became a tomb in which Casey wept and talked to herself and then stopped talking. She wandered the streets she had always wandered, while inside she unraveled in loneliness. Some nights she stood at the perimeter, almost wishing the weapons assault would resume—and this time be successful. She toyed with the idea of lowering the shield, but she was past that.
At night, stars encrusted the New Mexico sky, a bed of diamonds to hold the yellow rind of the moon. Suddenly Casey’s attention quickened. A point of light sped silently across the sky. She sat forward, making the chair creak. But it was only a weather sat, remnant of the conquered human race, not a humanitarian mission from Luna. She stood up and walked through the broken door into her house.
• • • •
After a month’s absence, she returned to the generator building. It had taken that long to believe again in the possibility of hope. She dragged her feet the whole way, indulged detours, pretended she wasn’t hoping, and finally approached the door. Something rapped against it from the other side. Casey stopped—then ran the rest of the way. When she wrenched open the door, the legless Surrogate lay on the floor, one arm raised.
“You were gone a long time, Casey Stillman,” it said. “I was worried.”
She swallowed. “I’m here now.”
• • • •
Casey took the Surrogate with her when she went to the warehouse for supplies. MREs lasted forever and there were enough of them to feed a thousand soldiers for a year. She placed the Surrogate’s torso and paint-can head on the cart and pulled it behind her, the way Casey’s mother had pulled her in the red wagon. The sound of the wheels was like a memory echoing up a long tunnel. Casey looked over her shoulder. The Surrogate’s blue eyes watched her.
“They’re really coming, aren’t they,” Casey said. “The Moonites.”
“Yes,” the head in the wagon replied.
The Surrogate was always right.