The gun shuddered in my hands. The harpoon shot out, snaking a silver rope behind it. For a moment I thought I’d missed. The harpoon seemed to sail over Himmell’s shoulder. But then I saw that one prong had gone through his suit, pinning him to the wall. The American stared at me.
“Good gun!” I said. And dropped it. Himmell lunged forward, but he wasn’t going anywhere. He was stuck there like a German calendar.
“You little . . . !” he began.
I didn’t want to hear him. I found another fire exit and this time I managed to get out of Selfridges without being stopped. I crossed the road and made my way around the front of Marks and Spencer. I was relieved to find Lauren waiting for me.
“What kept you?” she said.
“You got away okay?” I asked.
“Sure. Gott could hardly walk, let alone run. Himmell was in better shape.”
“Yeah,” I agreed. “He was.”
Lauren sighed. “Well, that was a waste of time,” she said. “We didn’t learn anything.”
I thought back to the food department, to the things I had seen. And suddenly I understood. It was as if I’d known all along, only someone had to sock me on the jaw to make me realize it. I smiled. Johnny Naples must have smiled that way. Lauren saw it. “Come on . . .” I said.
The same taxis and the same buses were jammed in the same place as we crossed Oxford Street again. We got back on the subway. It would take us to South Kensington, where we’d get a bus.
I knew. But I had to be sure.
INFORMATION
“The bar code,” I said.
“The what?”
“Those little black-and-white lines you get on the things you buy.”
“What about them?”
I pulled the Maltesers out of the shoulder bag and showed them to Lauren. “Look,” I said. “You see? It’s got a bar code.”
“So what?”
“That’s what they were using in Selfridges. The girl was passing her products over a scanner and the scanner was telling the cash register how much the products cost.” Lauren looked blank, so I went on. “Maybe if you pass this bar code over a scanner, it’ll do something different.”
“Like what?”
“I don’t know. That’s what we’re going to find out.”
I needed a science lesson in a hurry and for once in my life I was sorry school had shut for the holidays. But I had another idea. Journalists write about technology and things like that. They know a little bit about everything. And I knew a journalist: Clifford Taylor, the guy who’d interviewed Herbert and me. He’d been at the Falcon’s funeral, too, so I figured he must still work on the same newspaper, the Fulham Express. That was where we were heading now. I had to be sure that I was right.
Nobody reads the Fulham Express, but everybody who lives in Fulham gets it. They don’t have any choice. It’s one of those free newspapers that come uninvited along with a shower of plumbers’ business cards, taxi telephone numbers, and special offers from Reader’s Digest. It’s delivered every Wednesday in the morning. And you can see it every Wednesday, in the afternoon, stuffed into trash cans or drinking up the dirt in the gutter.
We took a bus all the way down the Fulham Road, past Herbert’s flat, to the bottom—Fulham Broadway. This was the Fulham Road at its worst: dirty in the rain, dusty in the sun, always run-down and depressing. I’d occasionally walked past the office of the Fulham Express, but I’d never been inside before. It was on the main road, next to a bank. Lauren and I climbed up a flight of stairs and found ourselves in a single, rectangular room with a printing press at one end and a photocopying machine at the other. In the middle there were two tables, piled high with newspaper clippings. The room must have been a dance studio at one time because it had mirrors all the way down one wall, making it seem twice as big as it was. Even so, it was small.
Clifford was there, feverishly working on a story that in a few days someone would use to wrap their fish and chips. I coughed, and when he didn’t respond, I walked up to him. He was the only person there.
“Clifford . . .” I said.
“Yes?” He looked up.
“You don’t remember me?”
“If you’re from the dance class, you’re too early. The newspaper has the room until five—”
“I’m Nick Diamond.”
He took his glasses off and wiped them. There were sweat stains under his arms and his acne had grown worse. He was a mess. I doubted if he could even spell “personal hygiene.” “Nick who?” he asked.
“Diamond.” I glanced at Lauren, who shrugged. “You interviewed me,” I reminded him. “My brother’s a private detective.”
Now he did remember. “Of course! Absolutely! How’s it going? There’s not much call for private detectives in Fulham—”
“I know,” I interrupted. Clifford liked talking. When he interviewed us, he’d talked more than we had. “I was wondering if you could help me,” I said.
“Sure. Sure.”
“It’s a sort of scientific question. Do you know anything about shopping?”
“Shopping?” He frowned. “I don’t think I know anyone called Shopping. There’s Chopin . . . but he was a composer, not a scientist.”
“No.” I sighed. “I’m talking about shops. And about bar codes. I want to know how they work.”
Clifford ran a hand through his hair. There wasn’t that much left for him to run it through. In fact, he had more dandruff than actual hair. “Okay.” He leaned back and put his feet up on the desk. “Technology is mainly about one thing: information. The electronic storage and transmission of information. Computers store information. Satellites send information. But all this information isn’t written out like a book. No way. It’s turned into what’s known as digital information.
“What does digital information look like? Well, in the old days it would have been a hole punched into a computer tape. There are holes in the modern compact disc, too—although they’re too small to see. And a bar code is another form of digital information. It’s as simple as that.
“All products have a bar code on them these days. If you look at them, you’ll see that there’s a number with thirteen digits underneath it. That’s all a bar code is. A number—a unique number that can tell the computer everything it needs to know.”
I’d taken out the box of Maltesers again while he talked. Clifford’s eyes lit up when he saw it. He leaned forward and took it.
“Take this box,” he said. “Here’s the bar code on the bottom.” He pointed to the strip of blue-and-white lines in the left-hand corner. “Part of it would tell the computer that this is a product made by Mars. Another part of it would tell the computer that it’s a box of Maltesers, that it weighs so much and costs so much. It could even remind the shopkeeper to stock up.”
“How does the computer read the bar code?” I asked.
“Well, that’s all done with lasers,” Clifford explained. “There’s a sort of little window built into the counter near the cash register. The person who’s sitting there passes the box of Maltesers—or whatever—over it. Now, behind the window there’s a laser scanner. The salesclerk could use a light-emitting diode, which is the same sort of thing, but either way, the light hits the bar code. Are you with me so far?”
I wasn’t sure, but I nodded anyway. If I’d learned one thing from science lessons at school, it was this. When scientific types start explaining things, it’s hard enough to follow. But when they start explaining the explanations, that’s when you really get lost.
“All right.” He nodded. “The light beams hit the bar code. Now, the dark lines don’t reflect light. Only the white ones do that. So only some of the light gets reflected. And somewhere inside that little window there’s a photodetector, which is a clever machine that produces a pulse of electricity whenever you shine a light on it. Do you see? As you slide the bar code over the window, the shining light hits the lines. Some of it is reflected back onto the photodetector, which gives out a ‘bleep’ for every white line. It’s the ‘bleep’ that’s the digital information sent to the computer. Almost like Morse code. And that’s how the computer knows what the product is!”