Penumbra lifts his hands and waves them at me, shooing me away from the desk. “Go home now. You have witnessed something rare, and more meaningful than you know. Be grateful for it. And drink your scotch, my boy! Drink!”

  I swing my bag up onto my shoulder and empty my cup in two stiff gulps.

  “That,” Penumbra says, “is a toast to Evelyn Erdos.” He holds the sparkling gray book aloft, and speaks as though addressing her: “Welcome, my friend, and well done. Well done!”

  THE PROTOTYPE

  THE NEXT NIGHT, I enter as usual and wave hello to Oliver Grone. I want to ask him about Eric, but I don’t quite have the language for it. Oliver and I have never talked directly about the weirdness of the store. So I start like this:

  “Oliver, I have a question. You know how there are normal customers?”

  “Not many.”

  “Right. And there are members who borrow books.”

  “Like Maurice Tyndall.”

  “Right.” I didn’t know his name was Maurice. “Have you ever seen somebody deliver a new book?”

  He pauses and thinks. Then he says simply: “Nope.”

  As soon as he leaves I am a mess of new theories. Maybe Oliver’s in on it, too. Maybe he’s a spy for Corvina. The quiet watcher. Perfect. Or maybe he’s part of some deeper conspiracy. Maybe I’ve only scratched the surface. I know there are more bookstores—libraries?—like this, but I still don’t know what “like this” means. I don’t know what the Waybacklist is for.

  I flip through the logbook from front to back, looking for something, anything. A message from the past, maybe: Beware, good clerk, the wrath of Corvina. But no. My predecessors played it just as straight as I have.

  The words they wrote are plain and factual, just descriptions of the members as they come and go. Some of them I recognize: Tyndall, Lapin, and the rest. Others are mysteries to me—members who visit only during the day, or members who stopped visiting long ago. Judging by the dates sprinkled through the pages, the book covers a little over five years. It’s only half-full. Am I going to fill it for another five? Am I going to write dutifully for years with no idea what I’m writing about?

  My brain is going to melt into a puddle if I keep this up all night. I need a distraction—a big, challenging distraction. So I lift my laptop’s lid and resume work on the 3-D bookstore.

  Every few minutes I glance up at the front windows, out into the street beyond. I’m watching for shadows, the flash of a gray suit or the glint of a dark eye. But there’s nothing. The work smooths away the strangeness, and finally I’m in the zone.

  If a 3-D model of this store is actually going to be useful, it probably needs to show you not only where the books are located but also which are currently loaned out, and to whom. So I’ve somewhat sketchily transcribed my last few weeks of logbook entries and taught my model to tell time.

  Now the books glow like lamps in the blocky 3-D shelves, and they’re color-coded, so the books borrowed by Tyndall light up blue, Lapin’s green, Fedorov’s yellow, and so on. That’s pretty cool. But my new feature also introduced a bug, and now the shelves are all blinking out of existence when I rotate the store too far around. I’m sitting hunched over the code, trying in vain to figure it out, when the bell tinkles brightly.

  I make an involuntary chirp of surprise. Is it Eric, back to yell at me again? Or is it Corvina, the CEO himself, come at last to visit his wrath upon—

  It’s a girl. She’s leaning halfway into the store, and she’s looking at me, and she’s saying, “Are you open?”

  Why, yes, girl with chestnut hair cropped to your chin and a red T-shirt with the word BAM! printed in mustard yellow—yes, as a matter of fact, we are.

  “Absolutely,” I say. “You can come in. We’re always open.”

  “I was just waiting for the bus and my phone buzzed—I think I have a coupon?”

  She walks straight up to the front desk, pushes her phone out toward me, and there, on the little screen, is my Google ad. The hyper-targeted local campaign—I’d forgotten about it, but it’s still running, and it found someone. The digital coupon I designed is right there, peeking out of her scratched-up smartphone. Her nails are shiny.

  “Yes!” I say. “That’s a great coupon. The best!” I’m talking too loud. She’s going to turn around and leave. Google’s astonishing advertising algorithms have delivered to me a supercute girl, and I have no idea what to do with her. She swivels her head to take in the store. She looks dubious.

  History hinges on such small things. A difference of thirty degrees, and this story would end here. But my laptop is angled just so, and on my screen, the 3-D bookstore is spinning wildly on two axes, like a spaceship tumbling through a blank cosmos, and the girl glances down, and—

  “What’s that?” she says, one eyebrow raised. One dark lovely eyebrow.

  Okay, I have to play this right. Don’t make it sound too nerdy: “Well, it’s a model of this store, except you can see which books are available …”

  The girl’s eyes light up: “Data visualization!” She’s no longer dubious. Suddenly she’s delighted.

  “That’s right,” I say. “That’s it exactly. Here, take a look.”

  We meet halfway, at the end of the desk, and I show her the 3-D bookstore, which is still disappearing whenever it spins too far around. She leans in close.

  “Can I see the source code?”

  If Eric’s malevolence was surprising, this girl’s curiosity is astonishing. “Sure, of course,” I say, toggling through dark windows until raw Ruby fills the screen, all color-coded red and gold and green.

  “This is what I do for work,” she says, hunching down low, peering at the code. “Data viz. Do you mind?” She gestures at the keyboard. Uh, no, beautiful late-night hacker girl, I do not mind.

  My limbic system has grown accustomed to a certain (very low) level of human (female) contact. With her standing right next to me, her elbow poking me just the tiniest bit, I basically feel drunk. I’m trying to formulate my next steps. I’ll recommend Edward Tufte, The Visual Display of Quantitative Information. Penumbra has a copy—I’ve seen it on the shelf. It’s huge.

  She’s scrolling fast through my code, which is a little embarrassing, because my code is full of comments like Hell, yeah! and Now, computer, it is time for you to do my bidding.

  “This is great,” she says, smiling. “And you must be Clay?”

  It’s in the code—there’s a method called clay_is_awesome. I assume every programmer writes one of those.

  “I’m Kat,” she says. “I think I found the problem. Want to see?”

  I’ve been struggling for hours, but this girl—Kat—has found the bug in my bookstore in five minutes flat. She’s a genius. She talks me through the debugging process and explains her reasoning, which is quick and confident. And then, tap tap, she fixes the bug.

  “Sorry, I’m hogging it,” she says, swiveling the laptop back to me. She pushes a lock of hair back behind her ear, stands up straight, and says, with mock composure, “So, Clay, why are you making a model of this bookstore?” As she says it, her eyes follow the shelves up to the ceiling.

  I’m not sure if I want to be completely honest about the deep strangeness of this place. Hello, nice to meet you, I sell unreadable books to weird old people—want to get dinner? (And suddenly I am gripped with the certainty that one of those people is going to come careening through the front door. Please, Tyndall, Fedorov, all of you: Stay home tonight. Keep reading.)

  I play up a different angle: “It’s sort of a history thing,” I say. “The store’s been open for almost a century. I think it’s the oldest bookstore in the city—maybe the whole West Coast.”

  “That’s amazing,” she says. “Google’s like a baby compared to that.” That explains it: this girl is a Googler. So she really is a genius. Also, one of her teeth is chipped in a cute way.

  “I love data like this,” she says, nodding her chin toward my laptop. “Real-world data.
Old data.”

  This girl has the spark of life. This is my primary filter for new friends (girl- and otherwise) and the highest compliment I can pay. I’ve tried many times to figure out exactly what ignites it—what cocktail of characteristics comes together in the cold, dark cosmos to form a star. I know it’s mostly in the face—not just the eyes but the brow, the cheeks, the mouth, and the micromuscles that connect them all.

  Kat’s micromuscles are very attractive.

  She says, “Have you tried doing a time-series visualization?”

  “Not yet, not exactly, no.” I do not, in fact, even know what that is.

  “At Google, we do them for search logs,” she says. “It’s cool—you’ll see some new idea flash across the world, like a little epidemic. Then it burns out in a week.”

  This sounds very interesting to me, but mostly because this girl is very interesting to me.

  Kat’s phone makes a bright ping and she glances down. “Oh,” she says, “that’s my bus.” I curse the city’s public transit system for its occasional punctuality. “I can show you what I mean about the time-series stuff,” she ventures. “Want to meet up sometime?”

  Why, yes, as a matter of fact I do. Maybe I’ll just go ahead and buy her the Tufte book. I’ll bring it wrapped in brown paper. Wait—is that weird? It’s an expensive book. Maybe there’s a low-key paperback edition. I could buy it on Amazon. That’s stupid, I work at a bookstore. (Could Amazon ship it fast enough?)

  Kat is still waiting for me to answer. “Sure,” I squeak.

  She scribbles her email address on one of Penumbra’s postcards: [email protected]—ofcourse—gmail.com. “I’ll save my coupon for another time,” she says, waving her phone. “See you later.”

  As soon as she leaves, I log in to check my hyper-targeted ad campaign. Did I accidentally check the box that said “beautiful”? (What about “single”?) Can I afford this introduction? In pure marketing terms, this was a failure: I did not sell any books, expensive or otherwise. Actually, I’m a dollar in the hole, thanks to the scribbled-on postcard. But there’s no reason to worry: from my original budget of eleven dollars, Google has subtracted just seventeen cents. In return, I have received a single ad impression—a single, perfect ad impression—delivered exactly twenty-three minutes ago.

  ———

  Later, after an hour of late-night isolation and lignin inhalation have sobered me up, I do two things.

  First: I email Kat and ask her if she wants to get lunch tomorrow, which is a Saturday. I might sometimes be faint of heart, but I do believe in striking while the iron is hot.

  Then: I google “time-series visualization” and start work on a new version of my model, thinking that maybe I can impress her with a prototype. I am really into the kind of girl you can impress with a prototype.

  The idea is to animate through the borrowed books over time instead of just seeing them all at once. First, I transcribe more names, titles, and times from the logbook into my laptop. Then I start hacking.

  Programming is not all the same. Normal written languages have different rhythms and idioms, right? Well, so do programming languages. The language called C is all harsh imperatives, almost raw computer-speak. The language called Lisp is like one long, looping sentence, full of subclauses, so long in fact that you usually forget what it was even about in the first place. The language called Erlang is just like it sounds: eccentric and Scandinavian. I cannot program in any of these languages, because they’re all too hard.

  But Ruby, my language of choice since NewBagel, was invented by a cheerful Japanese programmer, and it reads like friendly, accessible poetry. Billy Collins by way of Bill Gates.

  But, of course, the point of a programming language is that you don’t just read it; you write it, too. You make it do things for you. And this, I think, is where Ruby shines:

  Imagine that you’re cooking. But instead of following the recipe step-by-step and hoping for the best, you can actually take ingredients in and out of the pot whenever you want. You can add salt, taste it, shake your head, and pull the salt back out. You can take a perfectly crisp crust, isolate it, and then add whatever you want to the inside. It’s no longer just a linear process ending in success or (mostly, for me) frustrating failure. Instead, it’s a loop or a curlicue or a little scribble. It’s play.

  So I add some salt and a little butter and I get a prototype of the new visualization working by two in the morning. Immediately I notice something strange: the lights are following one another.

  On my screen, Tyndall will borrow a book from the top of aisle two. Then, in another month, Lapin will ask for one from the same shelf. Five weeks later, Imbert will follow—exactly the same shelf—but meanwhile, Tyndall has already returned and gotten something new from the bottom of aisle one. He’s a step ahead.

  I hadn’t noticed the pattern because it’s so spread out in space and time, like a piece of music with three hours between each note, all played in different octaves. But here, condensed and accelerated on my screen, it’s obvious. They’re all playing the same song, or dancing the same dance, or—yes—solving the same puzzle.

  The bell tinkles. It’s Imbert: short and solid, with his bristly black beard and sloping newsboy cap. He hoists his current book (a monstrous red-bound volume) and pushes it across the desk. I quickly scrub through the visualization to find his place in the pattern. An orange light bounces across my screen, and before he says a word, I know he’s going to ask for a book right in the middle of aisle two. It’s going to be—

  “Prokhorov,” Imbert wheezes. “Prokhorov must be next.”

  Halfway up the ladder, I feel dizzy. What’s going on? No daredevil maneuvers this time; it’s all I can do to keep my balance as I pull slim, black-bound PROKHOROV off the shelf.

  Imbert presents his card—6MXH2I—and takes his book. The bell tinkles, and I am alone again.

  In the logbook, I record the transaction, noting Imbert’s cap and the smell of garlic on his breath. And then I write, for the benefit of some future clerk, and perhaps also to prove to myself that this is real:

  Strange things are afoot at Mr. Penumbra’s 24-Hour Bookstore.

  MAXIMUM HAPPY IMAGINATION

  … CALLED SINGULARITY SINGLES,” Kat Potente is saying. She’s wearing the same red and yellow BAM! T-shirt from before, which means (a) she slept in it, (b) she owns several identical T-shirts, or (c) she’s a cartoon character—all of which are appealing alternatives.

  Singularity Singles. Let’s see. I know (thanks to the internet) that the Singularity is the hypothetical point in the future where technology’s growth curve goes vertical and civilization just sort of reboots itself. Computers get smarter than people, so we let them run the show. Or maybe they let themselves …

  Kat nods. “More or less.”

  “But Singularity Singles …?”

  “Speed-dating for nerds,” she says. “They have one every month at Google. The male-to-female ratio is really good, or really bad. Depends who—”

  “You went to this.”

  “Yeah. I met a guy who programmed bots for a hedge fund. We dated for a while. He was really into rock-climbing. He had nice shoulders.”

  Hmm.

  “But a cruel heart.”

  We are in the Gourmet Grotto, part of San Francisco’s gleaming six-floor shopping mall. It’s downtown, right next to the cable-car terminus, but I don’t think tourists realize it’s a mall; there’s no parking lot. The Gourmet Grotto is its food court, probably the best in the world: all locally grown spinach salads and pork belly tacos and sushi sans mercury. Also, it’s belowground, and it connects directly to the train station, so you never have to walk outside. Whenever I come here, I pretend I’m living in the future and the atmosphere is irradiated and wild bands of biodiesel bikers rule the dusty surface. Hey, just like the Singularity, right?

  Kat frowns. “That’s the twentieth-century future. After the Singularity, we’ll be able to solve those problems.” She cracks
a falafel in two and offers me half. “And we’ll live forever.”

  “Come on,” I say. “This is just the old dream of immortality—”

  “It is the dream of immortality. So?” She pauses, chews. “Let me put it a different way. This is going to sound strange, especially because we just met. But, I know I’m smart.”

  That’s definitely true—

  “And I think you’re smart, too. So why does that have to end? We could accomplish so much if we just had more time. You know?”

  I chew my falafel and nod. This is an interesting girl. Kat’s utter directness suggests homeschooling, yet she is also completely charming. It helps, I guess, that she’s beautiful. I glance down at her T-shirt. You know, I think she owns a bunch that are identical.

  “You have to be an optimist to believe in the Singularity,” she says, “and that’s harder than it seems. Have you ever played Maximum Happy Imagination?”

  “Sounds like a Japanese game show.”

  Kat straightens her shoulders. “Okay, we’re going to play. To start, imagine the future. The good future. No nuclear bombs. Pretend you’re a science fiction writer.”

  Okay: “World government … no cancer … hover-boards.”

  “Go further. What’s the good future after that?”

  “Spaceships. Party on Mars.”

  “Further.”

  “Star Trek. Transporters. You can go anywhere.”

  “Further.”

  I pause a moment, then realize: “I can’t.”

  Kat shakes her head. “It’s really hard. And that’s, what, a thousand years? What comes after that? What could possibly come after that? Imagination runs out. But it makes sense, right? We probably just imagine things based on what we already know, and we run out of analogies in the thirty-first century.”

  I’m trying hard to imagine an average day in the year 3012. I can’t even come up with a half-decent scene. Will people live in buildings? Will they wear clothes? My imagination is almost physically straining. Fingers of thought are raking the space behind the cushions, looking for loose ideas, finding nothing.