The last robot

Journal name:
Nature
Volume:
541,
Page:
568
Date published:
DOI:
doi:10.1038/541568a
Published online

It's the category that counts.

Illustration by Jacey

Seventy-six years after the world ended, the last robot and the last human met on a windswept plateau.

The last robot had been located in her repository, monitoring Earth as she'd been programmed to do, when an energy spike registered on the weakening sensors. With transportation in ruins, it took the last robot 432 days to reach the place where the energy spike had originated and locate the unsealed cryostasis tubes.

By that time all the humans who had been in them were dead, save one.

The last robot went about her duties anyway. A census must be taken; order must be imposed upon this data point of one, to the best of her ability.

She found the last human up on the plateau, a person-shaped figure wrapped in layers of cloth against the too-harsh wind, arranging racks of edible fungus to dry in the too-bright sun.

“Greetings,” the last robot said, in English first, as that was the language this area had formerly used. “I am R47-821, assigned custodian of the Cairo repository. My mission is the preservation of the human species.”

“Oh,” the last human said. “How's that going?”

The last robot had the definition of irony in her memory banks, but did not recognize the application. “Suboptimal,” she answered. “You are the only living human I am registering. Projection is species death within an upper bound of ten decades.”

The last human's expression darkened with the sorrow of one who has held out hope, only for it to come to naught. “Well. On the bright side, I suppose it's nice to hear you give my lifespan such a wide latitude.”

“Ten decades is the upper bound. Probability projects —”

“That's ok,” the last human said hastily. “I don't need to know. How did you find me?”

“I was monitoring,” the last robot said. “Projections 433 days ago were that species death had already occurred, but a small but finite probability existed that some cryostasis chambers had remained intact. I monitored.”

“I'm glad,” the last human said. “It's been quite lonely, with no one to talk to. I had hoped ... but never mind. So what happens now?”

“I must categorize you,” the last robot said.

“Categorize me?”

“Yes. In order to isolate the optimal decision tree for species survival.”

“Are there any qualifying decision trees when the total population is one person?” the last human asked.

The last robot's processors flipped through the possible recovery models. “No. But I can project based on the likelihood of survival of any other cryostasis units.”

“And what is that likelihood?”

“It now approximates to zero, but the error margin is finite.”

The last human's features contorted, as if battling whether to weep or laugh. “I guess that's hope for you.”

“I do not hope,” the last robot said. “I assign probabilities. It is my job to help humans choose the probabilistic paths that will best lead to species survival. For that I need data.”

“Well, R47-821,” the last human said, coming forward and clapping a friendly hand on the robot's chassis, “who am I to stop you from doing your job? Categorize away.”

“What is your name?” the last robot began.

“Val,” the last human answered. “Val Matsumierrez.”

“What is your profession?”

“Applied climatologist,” Val said. “Or at least, I was. That's now either an entirely irrelevant profession or the most relevant one of all.”

“What is your age?”

“Forty-eight when I went into cryo. So at least forty-nine now, subjectively.”

“Are you a male or a female?”

“Neither.”

The last robot stopped. “That is not one of the options. Everyone must have a category.”

“I'm the last human,” the last human said. “I'm 100% of the population. And you're still telling me I don't exist?”

“You must have a category,” repeated the last robot, who had been programmed only with species procreation in mind.

“No,” the last human said. “I'm the last goddamn human. There's no earthly reason for me to need a category.”

“Everyone must have a category.”

“Not everyone.” The last human smiled suddenly, with the bent sharpness of the reckless and free. “You don't have one. I don't have one. We'll sit here together, the last beings in the world, both category-less till the end of days.”

“I do have a category. I am female,” the last robot corrected, and pointed to the faded markings where someone had painted eyelashes on her metal face.

Val choked and began to laugh.

The last robot didn't know what was funny. But the last human kept laughing and laughing, and eventually had to sit down and laugh some more, laughing until tears ran down their face in the windswept sun.

Author information

Affiliations

  1. S. L. Huang has a degree in maths from the Massachusetts Institute of Technology, and now writes mathematically slanted science fiction, starting with the novel Zero Sum Game.

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