“That’s Jimmy,” Lauren whispered, recognizing James Walker’s freckled cheeks and carrot-red hair. “What’s left of him…”
Suzanne took Lauren by the arm. “That’s all we needed, Dr. Sullivan. You can go home as soon as Joel can raise our chopper in Mexico City. It’s our big Sikorsky Crane, the CH fifty-three that brought us the lab. Our backup group is standing by in case we need anything else. I’m sure Mason won’t mind asking them to pick you up. It’s noisy as hell and slower than Christmas, but it’ll get you to the next commercial flight to the States.”
Pushing brush and vines aside, Lauren followed Suzanne back toward the temple, feeling completely devoid of emotion. This had been the worst two days of her life and the thought of ending them sounded appealing, although she knew she would never escape the memories.
Getting out of this stupid orange space suit and going back to civilization held far more appeal, the way she felt now, than getting to know Mason better. Or did it? she wondered. She was becoming increasingly confused by her feelings toward him and even though nothing could ever come of it she still felt pangs of guilt over her feelings. It’s a shame, she thought, that he couldn’t be persuaded to ride back to Mexico City with her and perhaps spend a night or two decompressing from the stress of the search for the killer bug.
She shook her head. That would never happen, for she knew he was too dedicated to his job to even think of taking a day off until the bug was found and defeated.
A movement among the escoba trunks caught her eye and she stopped abruptly. “There he is again!” Lauren cried, pointing to a shirtless form running away from them into the jungle. “Do you see him? It’s that same Indian boy. I knew I wasn’t imagining it when I saw him last night!”
“I see him,” Suzanne replied, her tone a mixture of curiosity and doubt. “How the hell can he be out here running around in a hot zone without protection? Remember what happened to your friend, Dr. Matos? That boy ought to be sick as hell or dead by now.”
“Should we try to catch him?” Lauren asked.
“Hell no,” Suzanne replied. “Did you see the way he moved through the brush, as if it weren’t there? Plus, it’d be much too dangerous for us to go running through the jungle in our Racals, too easy to get a puncture and then we’d be laid up like poor Dr. Matos.”
Lauren continued to follow Suzanne back to the clearing, where four Racal-suited forms stood outside the mobile laboratory.
Lauren heard Suzanne mutter, “Someone isn’t here. We’re missing a team member somewhere.”
Lionel’s voice replied, “Have any of you seen Shirley?”
Before anyone could reply, Shirley pushed her way out of thick brush and said, “I was just a short way up the trail, making sure the soldiers are doing their job and keeping sightseers and the press off our backs and out of the hot zone.”
Mason, Shirley, and Jakes were in their Racals in the lab, printouts from the CDC mainframe computer known as Mamma spread before them. “These cultures have been growing for about twelve hours now and that should be enough,” Mason remarked, glancing at a digital clock on a wall of the lab.
Shirley leaned over petri dishes arranged on the counter. “Mason, these colonies are very similar to what I would expect from anthrax, only they’re slightly different.”
“How so?” Jakes asked. “It’s been twenty years since I looked at bacterial cultures. What are you looking for?”
“Anthrax is nonhemolytic, and that means colonies should grow on blood agar medium, and the grayish-white patches should have clean margins showing they’re not hemolyzing or destroying blood in the medium. Here,” she pointed to one of the culture dishes, filled with a dark reddish-brown jelly substance. “You can see these colonies have a small clear area around them, showing at least some hemolysis is taking place. That doesn’t fit with classical anthrax.”
Mason was across the room examining DNA probe test strips. “There are a couple of minor differences here, too. Not enough to show a different species, however there is a small but very distinct difference in the arrangement of amino acids in genetic coding for these bacteria.”
Shirley glanced down at another test strip, “Uh-oh, here’s another anomaly. The gamma-bacteriophage lysis test shows some differences.”
Exasperated, Jakes asked, “Now just what the hell does that mean?”
Shirley explained without the usual impatience found in her voice when she spoke to Jakes, “Virulence in anthrax, its ability to produce disease, depends on three components: edema toxin, lethal toxin, and capsular material. Without any one of these, the anthrax bacillus is unable to cause significant illness. The production of the two toxic factors is regulated in anthrax by one plasmid and the capsular component by a second plasmid.
“As you know from viruses, plasmids are small bits of chromosomal material that interact with the bacteria’s own chromosomes to determine its characteristics. In this bug, these appear a little different biochemically from the way classical anthrax plasmids should.”
Jakes knitted his brow thoughtfully. “Hey, if that’s what’s bothering you, maybe I can put one of these little bastards in my electron microscope and we can look inside the capsule and take a gander at its chromosomal makeup. Would that help?”
Shirley looked over at Mason and shrugged. “It may shed some light on what’s going on with these little buggers.”
While Shirley and Mason continued with their biochemical tests, Jakes took a specimen from one culture dish and prepared it for examination under his electron microscope. After roughly thirty minutes, he announced, “I’m ready over here.”
Shirley and Mason stood behind him, peering over his shoulder at the monitor screen of the giant microscope.
As Jakes twisted dials and controls, the image of a single bacillus grew on the screen, appearing as if they were journeying deep inside the bacteria’s capsule themselves.
Jakes pointed to the screen where a large, black circular object hovered in the meat of the bacteria. “Here’s the nucleus, where all the chromosomal material is. Watch as I increase the magnification.”
The picture slowly enlarged until it filled the screen, then enlarged further. “There are the bacteria’s chromosomes, and over there,” he pointed to one side of the nucleus, “near its outer edge are the plasmid components.”
“Wait a minute,” Shirley said, excitement raising her voice. “I see three plasmids, and anthrax is supposed to only have two!”
Mason stepped back, unconsciously attempting to rub his chin, instead stroking the hood of his Racal. “Shirley, if this is an ancient form of anthrax, do you suppose the third plasmid could be responsible for allowing it to be transmitted from person to person? We know present-day anthrax has only two plasmids, one for toxicity and one for capsular formation. What if the third was lost in some ancient mutation, causing anthrax to lose its ability to be spread in air-to-air transmission from one infected person to another?”
Shirley spread her palms. “Hell, chief, anything’s possible. This bug has had four hundred years to change, and so far this is the only difference we’ve found between what may be an older version and the present forms of anthrax.”
She pointed to the array of test strips and culture dishes on the counter behind them. “The extra plasmid could account for this bug’s ability to lyse or destroy red blood cells, and its capability to be spread by aerosol or droplet transmission. Of course, it’s going to take extensive DNA testing to determine exactly what chromosomes the extra plasmid contains and what its exact function is, and there is simply no way we’re equipped to do it here. That’s going to take all the facilities at the CDC lab in Georgia.”