“What’s up?” Jeremy asked as soon as they closed the door.
“He was getting calmer with time,” she said, going nervously through the contents of Novachenko’s duffel bag. “That shouldn’t have happened.”
“What do you want to do?”
“You keep on drilling him. I wanna run to the mobile lab; they must have some result on that sandwich by now. And I want to give them this,” she said, holding a travel-size can of hair spray, “maybe it’s got something to do with that sandwich, or maybe it has something to do with time.”
“Huh? Do you know you’re not making much sense?”
“Yeah, I do,” she replied and turned to leave. “But neither does a short-haired man carrying aloe vera hair spray on a flight.”
…66
The tractor-trailer took seven parking spaces along the white curb marked drop-off zone only. Black and windowless, the trailer bore the inscription “Federal Bureau of Investigation — Mobile Forensics” in gold lettering.
Alex didn’t waste time knocking; she hopped up the two steps and opened the door.
“Ah, Agent Hoffmann,” the female lab technician said, “I was just about to call you.”
She started to say she wasn’t an agent, but curiosity took precedence.
“What did you find?”
“You were right, there was something in that sandwich: E. coli SPAM.”
“Eww… gross. It looked like ham and cheese to me. How is this helpful?”
“No…” she chuckled. “SPAM as in steganography by printed arrays of microbes,” the technician clarified, smiling briefly and turning toward an LCD showing luminescent microorganisms, resembling little hot dogs piled on top of one another. “SPAM is an information encryption and transport technique, using fluorescent strains of Escherichia coli treated and arranged a certain way to represent the letters of the alphabet. In these microbe arrays, there are enough colors for anything you’d want to write.”
“How would someone grow these microbes and transfer them to a sandwich?”
“You arrange the microbes to represent the message, then grow them in a Petri dish.”
“Ahh… Petri dishes, now it makes sense. I’ve seen those at our suspect’s home,” Alex added, seeing how confused the tech seemed. “Please continue.”
“Then you transfer the cultured microbes to film, and ta-da! Your biofilm is ready for transport.”
“But I saw Smolin take a bite from one of these sandwiches,” Alex pushed back. “Why isn’t he sick, or dead?”
“These E. coli are genetically modified to be entirely safe. In case of trouble, a spy could eat all the evidence and be fine.”
“Great,” she grumbled. “Tell me please, how does one generate a message, exactly?” Alex asked.
“Seven different strains of E. coli were engineered to glow a different color under the right chemical and light conditions, by triggering fluorescence in a certain protein. The microbes are grown in rows of paired spots, each combination of two colors representing a letter or a number. For example, a yellow and an amber spot could represent the letter A. Here’s a sample decoded microbe array I found on the Internet, to give you an idea,” the technician said, pointing to a different screen, where chains of little colored circles lined up row after row in a matrix distribution.
“How does one do this? I’m guessing they’d need access to a sophisticated lab, right?”
“Maybe, maybe not. If you want to take the grassroots approach to generating SPAM biofilm, you wouldn’t need much; just some Petri dishes, a carefully modified antibiotic solution, culture medium, some LEDs, and… that’s about it,” the technician clarified, counting on her fingers.
“So how can we decode the message?”
“We can’t, not without the original growth environment. We’d need to regrow the bacteria in the same environment, or we would not obtain the right colors and the message would be completely indecipherable.”
“What?” Alex said, almost growling. “There must be something we can do to nail this bastard.”
“I’m afraid there’s nothing we can do. Again, if we use the wrong growth medium, the array will light up in the wrong sequences, and that won’t mean anything.”
“Could this type of message self-destruct?” Alex asked, suddenly remembering the small can of hair spray she had brought with her from Novachenko’s bag.
“Yes, it’s time sensitive; the microbe luminescence fades with time if not preserved, or fixated.”
“Could this be the fixating agent?” Alex asked, handing the technician the hair spray.
“Let me check,” the young woman said, cocking her head to the side and spraying a small amount of substance into a test tube, then inserting it into a gas chromatograph. A minute later, the machine chimed and displayed a chart filled with numbers.
“Yes,” the technician confirmed, “this is the fixating agent, that’s for sure. I’ll treat the biofilm with it and hope it will last enough for us to figure out how to decrypt it. We need to find its culture medium.”
“How would that look?” Alex pressed on.
“It could be anything. I’m guessing some kind of liquid or emulsion,” the tech added, “although he might not have it on him, that’s why SPAM is so secure.”
“What are you saying?” Alex asked in disbelief.
“You could have the encoded bacteria here, and have matching controlled growth medium on the other side of the border. No one would be able to grab it and decode it.”
“Still, we have to try,” Alex replied.
She pulled out her cell and called Jeremy.
“Hey, I need you to bring me everything this guy had on him, and I mean every—”
The trailer door opened and Jeremy walked in, carrying the rest of Novachenko’s luggage.
“That what you’re looking for?
The technician made room on the table for the luggage, and they all started going through the stuff, piece by piece. Alex almost disregarded a commercially wrapped gift set of cosmetics, containing makeup, lipstick, nail polish and clear coating, all with brand labels. Then she changed her mind and looked at that package in detail.
Alex picked the clear nail protector bottle, opened it and sniffed it. It stunk of acetone… no, that wasn’t it. No microbes could live or glow in acetone. She then smelled the nail polish. This one was almost odorless, except a faint, nearly imperceptible fruity smell. She handed it over to the tech.
“Is this it? Could this be it?” she asked impatiently.
The young technician tested it quickly and confirmed it had the chemical makeup of a bacterial growth medium.
“Yes!” Alex said. “Please tell me we can read the message now,” she said, clasping her hands in a pleading gesture.
“Yes, we can, if this is the right growth medium, and it is logical to assume it is. Now we can overlay the biofilm on the growth medium and the bacteria will light up, allowing us to read the message.”
“But isn’t the message encrypted?” Jeremy asked.
“Yeah, it is, but now it’s easy, it’s a simple alphabet encryption. Any deciphering software will be able to read it. We have CrypTool installed right here,” the tech said, turning toward another computer. “It will take an hour or so, Agent Hoffmann.”
“It’s Alex,” she said. “I’m not really an agent, you know.”
The technician smiled, a little confused.
“OK, then, let’s pick up a Russian spy,” Alex said, smiling widely for the first time in days.
“Hey, wait a second,” Jeremy said, “weren’t you opposed to picking up Smolin until we identify the backup asset, and his entire uplink network?”