NH3

by Stanley Salmons

  “Dr. Kramer, I think we should be dealing with the situation as it is now.”

  “Of course, I understand that this would suit you much better.”

  Her voice hardened. “It’s not a question of what suits me. It’s a question of survival. You’ve seen the atmospheric sampling data. Ammonia levels are on the rise again. Unless we act quickly we’ll be back to that threshold in a matter of weeks. Now I came here to ask you something. Are you prepared to listen?”

  His mouth set. “Go on.”

  “The biological teams are getting good results. We’re approaching the point where we need to test our solution in the field. I think we should be preparing for that now.”

  His expression was still sour. “What do you have in mind?”

  “I’ll speak in general terms. To be convincing, we need to conduct our tests in an area known to be badly affected by ammonia organisms. We’ll empty a canister of our material there. After a suitable interval we’ll take samples at different distances to see how effective it’s been and estimate the speed at which it’s spreading. There are people in the group who are experienced in taking such samples, myself included.”

  He said nothing for a while. Then he steepled his fingers and replied with great deliberation.

  “I’ll speak in general terms, too. You’re proposing to conduct a test of material of unknown efficacy in an area known to be badly affected. By definition, there are likely to be high levels of ammonia in such an area, and you are proposing to take a group of ordinary scientists out to do this?”

  “We’d be equipped with respirator masks, of course, in case of problems.”

  He shook his head. “Dr. Ferris, you are being remarkably naive. Do you really think I would permit our scientists to risk their lives in this way? We pay our military to do this kind of thing for us. Servicemen are trained and equipped to deal with dangerous situations and this falls precisely into that category. It can only be conducted as a military operation.”

  For a moment she was too stunned to speak. Then the words began to tumble out. “They won’t know what to sample or how to take the samples or how to preserve them. That’s our job!”

  “No, Dr. Ferris, it is not your job to get killed.”

  She sat back and steadied her breathing. She would try once more.

  “Dr. Kramer, we’re close to success now, but we have to move quickly. If we can run some convincing tests in the lab would you reconsider?”

  “Of course a convincing result in the lab would be absolutely essential before we even consider going into the field. But it does not change my view about who carries out the testing. When you have the material you wish to test, we will contact the US Navy and have them undertake the procedure for you.”

  “They could come back with useless samples! It would be a waste of precious time!”

  “When it comes to time-wasting, all I can say is that you should have thought of that earlier.”

  For a moment she gazed at him in disbelief, then got up and hurried out.

  Back in her room, Maggie sat down at her desk. She lowered her head into her hands and ran her fingers through her hair.

  The man’s impossible! He’s more interested in his own status than the fate of the world.

  Her mind was invaded by such a variety and profusion of richly uncharitable thoughts about Kramer and his motives that it left her astonished and a little ashamed.

  If things had been different she’d have told Terry straight away. He could handle it, all right – look how he dealt with Kolesnikov. He’d go to Kramer, and failing that to the President. But she couldn’t go to Terry, not now.

  She straightened up. There was a better way.

  CHAPTER 63

  Silvia, Matt, and Alain Laroche had called a lab meeting for Tuesday morning, and invited Maggie to join them. A computer screen on the bench at their side displayed a complete schematic of the plasmid Zak had used. Silvia and Matt could read the base sequences like a book.

  “This part is just the vector,” Matt explained. “The construct starts here – look, here’s the enhancer sequence and here’s the promoter sequence. Downstream you have the reporter gene – ”

  “The Green Fluorescent Protein.”

  “Yep, then there’ll be sequences for DNA-binding, regulation, and of course a bit for conjugation.”

  “Conjugation?” Maggie said. “Remind me.”

  “That’s the mechanism for passing the plasmid between bacteria. Some bacteria have it, cyanobacteria don’t. But whoever made this plasmid made damned sure it encoded everything it needed to transfer itself. That’s why it was so easy to transfect E. coli with it. We’ve been producing the protein hand over fist.”

  “All right,” Maggie said. “Let’s talk about that protein.”

  “Matt, can you get the 3D model up?” Silvia said.

  “Sure. Won’t take a moment. The supercomputer eats jobs like this for breakfast.”

  The protein molecule came up on the screen and he set it rotating slowly.

  “Okay, Matt, can you stop it there?” Silvia pointed. “Look, Maggie, you see this structure here? It’s called a zinc finger motif; it’s a classic DNA-binding domain. Now look, here’s another and here’s another. Three tandem repeats, corresponding to fifteen base pairs. I’m sure this is where the switch binds to the host DNA.”

  Maggie leaned forward, her whole body drilling with excitement. It was like viewing a murderer at the scene of a crime, the knife poised in his hand. “So there it is,” she breathed. “That’s where the switch attaches to the nitrogen-fixing sequence.”

  Matt said, “Whoever did this must have known just where he wanted it to bind.”

  Alain Laroche rubbed his lower lip. “The man’s a genius.”

  “Was,” Maggie corrected.

  “Was?”

  “Dr. Zak Gould was responsible for developing the plasmid, and yes, actually I think he was a genius. Unfortunately he was murdered.”

  Laroche’s eyebrows lifted and he looked slowly round at her. “Silvia said you had gone to look for him, but not that he was murdered. How did you find out?”

  “How? He was sitting no further away from me than you are now when he was shot.”

  “Mon Dieu!”

  “Was this guy working on his own?” Matt asked.

  “As far as we know, yes.”

  Matt shook his head. “Fucking genius is right. No question. What a goddamned waste!”

  Maggie nodded, her lips tight. Then she looked at the others. “So what’s next?”

  Laroche said, “It has been made easier for us, because the GFP tag is already present. So we cross-link all the proteins to the DNA, shear the DNA into short stretches, and use an antibody to the GFP to separate the tagged DNA sequence.”

  Maggie frowned. “Alain, that will tell us where in the host’s DNA the switch is acting, but I’m not sure we need this information at the moment. Our priority is to block the switch. Isn’t there a more direct way?”

  Matt looked at Silvia. “Gene silencing? Silvia, you’re the expert.”

  She nodded slowly. “Yes, we could design a small interfering RNA that would specifically target the construct. This we could introduce on our own plasmid. Then every strand of RNA made by the rogue plasmid would be destroyed, so the protein switch could never be manufactured.”

  “That sounds great, Silvia,” Maggie said.

  “Yes, but…” Her dark eyes narrowed thoughtfully. “Degradation of the target RNA relies on a protein complex. If it is not present in cyanobacteria we will have to add that to our plasmid. I will look into it.”

  “Silvia,” Alain said, “if you could let me have the sequence you need for the interfering RNA my group can get started on synthesizing it right away.”

  Matt said, “Why don’t you leave that part to me? We’ve got the entire sequence of Zak Gould’s construct. My people can run it through the online DNA databases and make sure we’re targeting a unique stretch. Sh
ouldn’t take more than an hour or two.”

  “Thank you, Matt,” Silvia said. “And I will look into the coding for the protein complex. Alain, you should have everything you need by the end of the day.”

  Alain rubbed his hands together. “Excellent,” he said. “Tomorrow we make a start on Maggie’s plasmid.”

  Sarah Bethany showed him into the President’s office. Harry Kinghorn looked up and smiled.

  “Hallo, Herbert. Have a seat. What’s on your mind?”

  Herbert Kramer took the chair and sat down, back straight, his hands resting in his lap, one cupped around the other.

  “I really didn’t feel I could delay this any longer, Mr. President.”

  Kinghorn frowned. “What’s the problem?”

  He took a deep breath. “I’m sorry to say that your group of so-called experts has continued to squander time and resources in a most unproductive fashion. First ammonia levels were allowed to rise above this so-called threshold, and you were persuaded to take that dreadful action in the north-west. Now ammonia levels are high all over again, and I see little sign of other solutions emerging. I’m deeply concerned.”

  The President took a deep breath. “What’s prompted this, Herbert?”

  Kramer lowered his head, apparently reluctant to part with the information, then raised it again. “Ferris came to see me the other day. I won’t bore you with the details but she made requests that were rash beyond reason. I regret to say the two of them have conducted this project badly from the outset and this was just another example of their incompetence and lack of judgement. My own approach would have yielded results more quickly. Perhaps,” he added, meeting the President’s eyes, “it would even have obviated the need to detonate that device in the Yellowstone system.”

  The mention of Yellowstone sent a small shock down Kinghorn’s spine.

  “I think we’re beyond that now Herbert,” he said coldly. “Why don’t you tell me what it is you are suggesting we do?”

  “President, we’re at a crisis point. If we don’t reach a solution in a matter of weeks it will be too late. These people are just blundering around. We should replace them as a matter of urgency.”

  “Replace them?” the President said, standing up and gripping the sides of his desk. “Replace them? Are you out of your mind?” His voice had risen to an angry growl, and Kramer shrank in his chair.

  “It’s because of Ferris and McKinley that we found out about this problem in the first place. It’s because of them that any of us are alive today. It’s because of them that we have a hope in hell of beating this thing!”

  “Mr. President, I’m simply…” began Kramer.

  “No, Herbert, I won’t listen to any more. You’ve done nothing but second guess these people the whole way through without coming up with a single solution yourself and I’m sick and tired of your dissension. You will remain in your post to oversee the success of this project. After that I’ll be expecting your resignation on my desk. Is that clear?”

  “Sir…”

  “Is that clear?” he roared.

  “Yes, Mr. President,” Kramer said weakly.

  Kinghorn’s voice dropped. “Good. Now get the hell out of my office.”

  Kramer got unsteadily to his feet and left without another word.

  Silvia and Matt gave Alain Laroche the required sequences on Tuesday night, as promised. Laroche’s team launched into action immediately and they had the construct by the end of the week. The success of the combined biological teams wasn’t the kind of thing that could be kept quiet in a closed community of scientists. Word got around and there was a buzz of excitement as they made their way towards the lecture theatre. The last four Friday meetings had been dominated by depressing reports from the groups monitoring ammonia levels. They badly needed some good news and at last Maggie could provide it. Terry turned the weekly meeting over to her and she lost no time in asking Silvia Mussini to come to the microphone.

  Silvia showed a schematic of the plasmid Zak had used. She explained how it produced a factor that switched on ammonia production and outlined how they’d identified the site responsible. Turning that site off would, she explained, neutralize completely the effect of Zak’s plasmid. And then, almost casually, she showed them the sequence data for the construct they’d designed to do the job, which Alain had already incorporated into a plasmid.

  It was what they’d been waiting for. The theatre broke into uproar. Everyone was on their feet. Silvia smiled and returned gracefully to her seat. Maggie went to the microphone and after allowing a little time raised a hand. The noise faded and people took their seats again.

  She grinned and spoke into the microphone: “There’s more.”

  In seconds everyone was sitting in an expectant hush.

  “All right,” she said. “At last we have a plasmid that can switch off the production of ammonia. But as you know, that isn’t enough. The rogue organisms are already widespread. To overtake them we have to make sure that the organism we use to introduce our plasmid has a selective advantage. That advantage is resistance to infection by a phage. Dr. Kolesnikov and Dr. Gupta have been selecting the phage that will do the job. Sergei?”

  Sergei took the podium. A rare smile lightened his normally thunderous countenance.

  “There is large number of phages. We need one which spread quickly and kill host. Also we prefer one which is already in ocean, so is not absolutely new to ecosystem. This bring down choice to a few. I like to thank Rajiv Gupta who do this with us.”

  Maggie glanced at Rajiv, who was nodding his head and smiling. It had worked out even better than she’d anticipated.

  Sergei had only one slide.

  “Here is.”

  It was an electron micrograph of the phage: a head, a stalk, and some long filaments. Sergei left the podium to applause.

  “And Rajiv…?” she said.

  Rajiv Gupta went to the microphone.

  “I am speaking here not only for myself but also for Pieter van der Rijt and Ulrich Lunsdorfer and their teams. You know that we are needing to put our plasmid into an organism, and this organism must be resistant to the phage. Pieter and Ulrich grew the candidate cyanobacteria, Sergei provided the phage, and we worked on the resistance. I don’t think you want to know the Latin name for this species, but here is a photograph that we took under the microscope. We think this is a very good organism for us, and it is most resistant to the phage Sergei just showed you.”

  He sat down to further applause.

  “So,” Maggie summarized, “thanks to the exceptional work of our teams we now have all of the major elements that we need: the phage, the organism, and the plasmid. The next step will be to insert the plasmid into the organism and grow it on. Then we’ll see how our engineered organism and the phage cope when they’re put up against the ammonia organisms in the laboratory. After that we can test it in the field. If all goes well we’ll arrange for quantity production. Terry, anything you want to add?”

  Terry joined her at the podium. “I’d just like to say how impressed we all are with the brilliant job you people have done. This project could have taken years, and you’ve solved all the major problems in just a few months. God knows there’s little time left: ammonia levels in the stratosphere are climbing fast. But it seems to me this could be a turning point. For the first time since Maggie Ferris and I discovered these organisms and realized what they could do, defeating them no longer seems totally out of the question. Let’s keep up the good work and thanks to all of you.”

  He started to clap and everyone joined in.

  There was a burst of excited conversation and a rattle of folding seats as the staff got up. They left the theatre in high spirits.

  Few of them noticed that Kramer was not present.

  CHAPTER 64

  The following Thursday the leaders of all the biological groups got together in Maggie’s room. Pieter van der Rijt and Ulrich Lunsdorfer had just concluded the laboratory testing of the
new organism and phage combination against a culture of the ammonia organisms. They had all seen the results and the atmosphere in the room was subdued.

  Maggie started the discussion. “Let’s take it stage by stage. Our plasmid works, right?”

  Silvia nodded. “There is no question about it. It switches off ammonia production completely.”

  “Okay, and the phage works.”

  Sergei and Rajiv nodded vigorously, and Rajiv answered: “It is most effective. And it does not kill our own organism.”

  “So are we getting plasmid exchange?”

  Pieter replied. “The evidence says we are. What is not so certain is the efficiency.”

  “Should we run more tests, Pieter? Perhaps on a larger scale?”

  He shook his head. “Maggie, you know it is very difficult to reproduce a natural environment in the lab – there are too many variables. Out there in the oceans there could be a completely different mix of organisms, there will be differences in temperature, light, the effects of currents and surface action, and so on. We could be successful in the lab and fail under real conditions, or fail in the lab when actually it would have been successful outside. I think we should test it in the field.”

  Ulrich lifted a hand. “I think this, too.”

  Matt spoke up. “We should go for it. We could spend weeks trying to sort things out in the lab. If the field test doesn’t work, we can always try again.”

  Silvia asked: “Maggie, how long would it take to set up a field test?”

  “Well, the idea would be to drop our organism into the ocean at a defined location, leave it for twelve hours or so, then collect samples at intervals of ten nautical miles in the direction of the surface currents. All that could be done in a couple of days. We’ll need to organize fresh supplies of ordinary ice and dry ice out there beforehand, but that’s not a problem. I think it all depends on how long it would take to grow up enough organism to do the test. Pieter?”