Paul Preuss

“Paul Preuss’ Human Error is one of the best science fiction novels of the year…. To find solid science and believable characters in the same book, you have to restrict yourself to a very exclusive list: Gregory Benford, Arthur Clarke, Frederick Pohl. Add Paul Preuss to that list.”

– Peter J. Heck,

Human Error (Large)

Watch for the new digital editions from Diversion Books

Human Error tells of a partnership between two computer scientists – Toby, a dapper playboy, and Adrian, a hopeless nerd – who become infected (literally) by their own invention, virus-based supercomputer. One is doomed; the other evolves into a new creature.

Read a chapter.



The words glowed greenly into existence on Toby’s screen: simple English sentences, sufficiently ambiguous even at their roots, enclosing the pun like an unlaid egg. He stroked a key and leaned back to let the machine do its thing.

He knew he had a long time to wait. Through the windows that formed one wall of the artificial-intelligence laboratory the mustard yellow cabinets of an ancient VAX 11/780 hummed in air-conditioned isolation, straining the hoary riddle through the algorithms of a program Toby had dubbed, hopefully, COMMONSENSE.

As if the rigors of his own program weren’t sufficient to stretch the VAX’s mental capacity, Toby time-shared the machine with three colleagues who were pursuing linguistic theories of their own.

While he waited, visions of supercomputers danced in his head, shiny new dedicated Crays shaped like miniature Roman temples, with nothing to do but run Toby Bridgeman’s programs twenty-four hours a day….

Minutes passed, and then there were new words on the screen: BECAUSE HE WAS A LITTLE MORE ON.

Toby blinked and suppressed a giggle. The damned thing had got the joke! By George, it’s got it! Though he was more than a foot too short to do a convincing Rex Harrison imitation, Toby had a mad urge to leap up dancing. He backed hesitantly away instead; what if the machine were only waiting for him to turn his back before letting the proof of its perspicacity dribble into the electricity?

“I say, fellows”—casually, now—“have a look at this.”

Dave Droege shambled over from his paper-strewn corner to peer at Toby’s screen. “The big moron and the little moron…,” he mumbled, moving his lips while he read (behind his back they called him Droege Bear). After half a sentence he stopped mumbling and just moved his lips. Finally he stopped moving his lips; under his bushy brows his eyeballs twitched.

Lassiter and Murch appeared, one beside each of Droege’s thickly upholstered shoulders. The three of them stood in silence a few seconds, and then Rodney Murch started absentmindedly scratching his balls; all his slacks had a furry patch in the crotch from when he was thinking. By now the tip of Droege’s blunt nose had turned pale with envy. “Very suggestive, Toby,” he said.

“Think it can do it again?” Tim Lassiter asked.

“Well, surely if—”

“Without coaching, I mean.” Lassiter crossed his muscular forearms over an expanse of plaid Pendleton shirt and tried to stare Toby down; a decade earlier he’d been a third-string wide receiver on the Princeton football team, and he had the notion he was frightening to men like Toby who were barely five and a half feet tall.

Murch kept thinking and scratching.

“Thanks, then,” said Toby, irritated now and letting it show. “I’ll call when I’ve something more interesting.” Like hell he would. He squeezed between his associates and rapped at the keyboard. The screen went blank.

Slowly the three wandered back to their corners, avoiding each other’s eyes, while Toby pondered this fresh evidence that his repeated successes were beginning to upset the delicate emotional ecology of the lab. Perhaps after all it was time to stop trying to be friends and start pressing the department chairman for a larger wedge of the ARPA grant pie.

His fingers flew over the keys, restating the riddle’s premise, repeating the question. This time the machine ran a mere thirty seconds before displaying the answer: BECAUSE SHE WAS A LITTLE MORE ON.

Take that, Lassiter. But what’s this “she”? Is the machine exhibiting nonsexist tendencies, or is it waffling?

He returned to his daydreams. Face the truth, old fellow, a Cray is not a serious option—fifteen million dollars or so, and that’s merely the hardware—but if you could just get the little VAX wholly to yourself…

This time his thoughts were interrupted by his name shouted from the hall: “Bridgeman!”

He stared at the apparition in the doorway, a wild-eyed, disheveled creature, far taller even than Tim Lassiter. For an instant Toby took him for some sort of violent protester come to bomb their defense-supported research—this was the University of California at Berkeley, after all, and old ways die hard.

Toby sat motionless as the man loped across the length of the cluttered room; his skinny body was draped in rags, his knobby head was crowned with blond hair resembling a Brillo pad, and his face—big-nosed, big-lipped, beetle-browed—was a mass of freckles. “You get any work done on this bag-biting piece of shit?” the man yelled at him, fleering at Toby’s fingerprint-smeared terminal and the decrepit VAX (was it really wheezing?) beyond the windows.

“I say, who the hell are you?” Toby sputtered. Idiotic thing to say. Don’t antagonize him. Toby was conscious of his ears glowing red, of the others staring at him.

“My name’s Storey. And by that silly accent, you’re Bridgeman in the flesh. But seriously now, how do you get anything done on a bletcherous kluge like this?”

“Storey?” Toby suppressed a giggle. One must be cool. With professorial calm he said, “Sorry, Storey, I don’t know who sent you to me, but we allow no flaming free-lance hackers in here before midnight.” Was this the notorious Adrian Storey?

“You’re the hacker, twerp.” Storey grinned alarmingly, displaying crooked yellow teeth. “I was just trying to talk your demented language. But with that accent—shit.”

“Quite,” said Toby, nettled. He had been made to understand that after ten years in the States he had practically no accent at all, but then people persist in telling you what they think you want to hear. “What can I do for you, uh…Stores, was it?”

“Say”—Storey looked genuinely upset—“don’t you know me? I’m Adrian Storey, man. From Compugen. I’m a big cheese—I’m bigger than Chuck E. Cheese himself. I’m the hottest germ jockey in the valley.”

Toby laughed outright. “Perhaps I’ve heard of you after all.”

“And all horribly true!” Storey shouted enthusiastically; his relief was evident. “I have a terrible temper! I’m ugly as sin.” He tapped his bulging skull. “But I’m smart.”

“Mmm.” Ugly, perhaps, but not lacking in self-awareness.

Abruptly Storey thrust out his right hand. “And so are you. That’s why I’m here.”

After the briefest pause Toby took the huge limp hand. “Dr. Storey.”

“Call me Adrian.”

“Adrian, then. In that case, I suppose I’m Toby.” On closer inspection he saw that Adrian Storey wasn’t really dressed in rags, although his faded blue jeans and dingy white shirt looked as if they hadn’t been changed in days. His running shoes were tattered remnants of their former selves, shreds of rubber and strands of nylon from which his sweat socks bloomed like gray patches of bread mold.

“Know thyself, that’s my motto,” Adrian said cheerfully.

Ugly, but sincere. And a mind reader. “But I see you’ve chosen to ignore the other piece of Delphic advice.”

“Yeah? What’s that?”

“Nothing in excess.” A cheap shot—Americans paid little attention to the classics, they were too busy creating the future.

Adrian seemed unperturbed. “Whatever you say. Listen, I haven’t got all day, why don’t you show me your stuff?”

He’d taken the edge again, and Toby reflected that it would not do to let this man keep it. “I have an idea, Adrian. Why don’t I show you what we’re doing here? While you’re in the neighborhood. If you’ve got a few minutes.”

“Yeah, yeah.” He had the grace to look uncomfortable.

“Nothing secret, I assure you,” said Toby cheerfully. (So don’t be shy, prick.)

“Look,” said Adrian. “Like I told you, I lack the social graces.”

Toby pulled a chair over for Adrian and moved his own closer to the keyboard. “Well, you were asking about hardware. Hardware’s of secondary importance to us, really—a computer is a computer is a computer”—the standard spiel, and what kind of fool does he think I take him for?—“but a program…now that can be something different…”

Adrian folded himself onto the chair and, as the minutes stretched, began lolling like a rag doll, while Toby painstakingly outlined his most recent attempts to shape programs that could generate diverse descriptions of linguistic objects and relate them in ways not only logical but, as Toby dearly hoped, pragmatic—and maybe creative as well.

That final goal, he was forced to admit, was still far in the future. But pragmatism was within reach.

The higher—the more “perfect”—the organism, the more slowly it developed, said Toby, and the same was true of programs capable of learning from experience. Only by acquiring knowledge about the world and expressing that knowledge in words, by experiencing success and failure in using words to influence the course of events—by talking up a storm and taking the consequences, like any two-year-old—only thus could a machine master language, beyond a few stock phrases manipulated according to structural rules of limited flexibility. Only by combining experience of language and the real world had a machine, on two occasions now—and here Toby dared hint at what was uppermost on his mind—been able to understand a pun.

But Adrian seemed bored by Toby’s lecture. From time to time he interrupted with such remarks as “You really happy waiting five minutes for that subroutine to run?” meanwhile leaning precariously backward in the folding chair, his thumbs hooked in his frayed pants pockets.

Toby assumed his questions were rhetorical.

When for the third time he got no answer, Adrian started howling. Howling like an infant, or so Toby thought, until he realized Adrian was singing.

“I once knew a woman named Salleee/ Her hair was as bright as theee sun/ But when I told Sally I luvved her/ She said I was no goddam fun…”

Toby had heard the tune before, but that time the words had had something to do with “acres of clams.”

Adrian really leaned into the chorus: “She said I was no goddam fun, me boys/ She said I was no goddam fun…”

By the second verse Lassiter had already walked out. Droege followed not long after.

“I play the guitar, too,” Adrian offered, interrupting himself. “But I can’t do both at once.”

“How sad it’s not with you.”

Adrian continued the serenade. “I once knew a woman named Suzeee/ Her thighs were like two marble slabs/ But when I told Suzie I loved her…”

With a grieved expression, his hands in his armpits, Murch, the last of Toby’s associates, now slouched out of the room.

Verses of escalating obscenity accompanied Toby’s struggles to converse by keyboard with the overburdened VAX. In a desperate attempt to impress Adrian enough to shut him up, Toby typed in the magic phrases: THE BIG MORON AND THE LITTLE MORON WERE WALKING ALONG THE EDGE OF A CLIFF. THE BIG MORON FELL OFF. WHY DIDN’T THE LITTLE MORON?

The machine hesitated barely an instant before displaying BECAUSE IT WAS NOT NEAR THE EDGE.

“Balls,” said Toby.

Adrian broke off and leaned toward him intently. “Look, Bridgeman, you do know it’s me who wants you at Compugen? You think Jack Chatterjee ever heard of you before I told him about you? I’ve read your stuff. I’ve run some of your programs, just for fun. I want you in on what I’m doing.”

“That’s nice,” said Toby. “But I haven’t an inkling of what that is.”

“Then come on,” said Adrian, grabbing Toby by the elbow and almost lifting him out of his chair. “I’m going to have to sneak you in—our stuff really is secret.” He looked down at Toby. “But that won’t be hard. I can’t believe you’re this short.”

Whenever Adrian was forced to stop for a traffic light, Toby caught a whiff of oily smoke seeping through the permanently open window on the passenger side of the ancient brown Saab. The car smelled like an outboard motor-boat, and Adrian steered it like one, swashing from lane to lane down jam-packed University Avenue toward the freeway.

A mile south along San Francisco Bay they came to the Compugen Corporation’s modernistic mission-style buildings: the two-story research institute, the administrative headquarters fronting Berkeley’s waterfront Aquatic Park, and the square expanse of the factory and warehouse backed up to the Santa Fe Railroad tracks. Squeezed between the freeway and the tracks, Compugen occupied a stretch of raw landscaping in an area where so many bioengineering firms had located in recent years—displacing the scavenger steel mills and chemical plants of times past—that wags had taken to calling the neighborhood Protein Valley.

Adrian rolled the Saab through a guarded gate and into the wide parking lot. Beside the short walkway to the door of the research building there were two empty spaces, one of them reserved for the handicapped, the other reserved for “Dr. Adrian Storey, Chief Scientist.”

Before they got out of the car Adrian rummaged in the glove compartment, found a plastic clip-on badge with somebody else’s picture on it, and told Toby to fasten it to the lapel of his linen sports jacket. The security guard in the lobby glanced at Toby’s face and then at the badge, and then up at Adrian. The guard smiled; the forms had been preserved. Toby was allowed inside to see, for the first time in his life, a bioelectronics research facility in action.

Chief Scientist Dr. Adrian Storey presided over a virtual maze of laboratories. In some the furnishings were mundane: long benches with outlets for electricity and spigots for gas and water, sinks, shelves of glassware and reagents stacked to the ceiling, and everywhere boxes of tissues and paper towels. The aisles were narrow, and technicians worked elbow to elbow. Toby was reminded of his science classes in public school; here the facilities were shiny and new, but to his surprise, the crowding and mess and noise were intense, worse than school days.

Toby was struck by the refrigerators. The walls were fairly lined with refrigerators, some with radiation symbols on their doors, others bearing the similar but somehow more menacing crab-clawed “biological hazard” warning signs. The monotony of refrigerators was only occasionally relieved by an egg incubator, a centrifuge, or a tubby autoclave. In time Toby was to learn that when biochemists fight for territory it is more likely to be wall space than floor space they scrap over—not so much a place to stand as a place to stand their refrigerators.


The biology labs were only the beginning. The maze continued through rooms devoted to electronics and optics, equipped with gleaming instruments of glass and steel, some of which Toby recognized, some completely alien.

They passed air-locked clean rooms where electronic circuitry was transformed from drawings into engraved crystal, etched into existence. They passed closed steel doors behind which thousands of small mammals were born, lived, and occasionally died—though most died on the bench—in stacked plastic and steel cages.

Finally Adrian brought him to the center of the labyrinth, the computer graphics room. They entered and closed the door behind them.

It was a dark place, silent except for the hiss of air conditioners. Toby imagined monumental supercomputers lurking beyond the walls, serving the giant video screens in front of him.

“Sit down. I’m gonna show you some bugs.” Adrian began busily tapping at a console keyboard with fingers that were remarkably nimble for their length: on the triple screens an extraordinarily twisted shape sprang into existence, a form that resembled nothing so much as a Henry Moore sculpture some vandal had splashed with gaudy paint.

“Here’s a classic,” said Adrian. “The coat protein of Type II polio. The proteins pack to form its shell.” He tapped the keys, and on the screens identical copies of the protein multiplied to form a spheroid, like a radar dome. “That’s the A form—and here’s the B.” The diagrammatic proteins reassembled themselves on the screen as Toby watched; the packing was different, but the resulting spheroid was much the same, forming a protective shell. “And inside the shell is this little string of RNA.”

“The RNA is what gives this geometric beast its killing power, then?”

“Shit, you’re a poet.”

Toby recoiled. “Really, must you speak only in scatological obscenities?”

“I was yelled at a lot when I was a kid,” said Adrian contritely.

“Spare me the self-analysis.” But Toby was mad at himself for using big words to ask dumb questions.

He looked on in fascination as Adrian played a manic game with his computer screens, conjuring up diagrams of involute protein structures, rolling them in space, examining their spines and undulations and cavities, flexing them, tearing them apart, making them dance. It went on a long time, and occasionally Adrian emitted groans and murmurs of delight as he put the graphic creatures through their paces.

Suddenly Adrian slumped in his chair. “Well, a virus can do only so many tricks. You’re probably wondering why I’m wasting my time with ’em.”

“Actually, it hadn’t occurred to me to ask,” Toby said. “I’m quite enchanted with your pretty pictures.”

“When it occurs to you to ask”—despite his evident determination to make a good impression, sarcasm crept into Adrian’s voice—“it’s because I’m looking for the simplest possible natural models for self-replicating systems. You really do know what we do here, don’t you?”

“Only that you make protein-based computer parts. Or so Dr. Chatterjee has led me to believe.”

“That’s only the first step,” said Adrian. “Cook ’em in a vat. We’ve already got that hacked. Now we’re trying to get them to build themselves. Viruses don’t really qualify, of course—they have to take over a cell’s machinery to reproduce. But the artificial organism I’m trying to build needs a scaffolding as simple as the coat protein of this virus—a molecule with no more than a couple of thousand atoms in it. Something that can be built, torn apart, modified with artificial enzymes I’ll provide. Following directions from a program I want you to write.”

“You’re trying to build a self-replicating computer?”

“Yeah. Maybe it’ll even look like this. But this is just the box the chips come in,” he said, tapping the screen. “The box-building program is only one of the things I need you for, though.”

“Oh? What else?”

Adrian turned from the console, the dim-colored light from the screens illuminating the head that was too big even for his gangling body, the features that were too broad even for his outsized head. Adrian Storey was not an attractive man, but Toby had already glimpsed in him the passionate dreaming, the capacity for excited discovery, of a bright and lonely child.

Adrian smiled. “I gotcha hooked, don’t I? You twerp.