Clarence had to play back the words in his head to make sure he wasn’t oversimplifying what he’d heard. Could it be that straightforward?
“So it’s a cure,” he said. “It kills the infection, but leaves our tissue alone?”
Tim thought for a moment. “Sort of. It depends on how long the person has been exposed. See, the catalyst is a really big molecule. You know anything about the blood-brain barrier?”
Clarence hesitated for a moment, wondering if Tim was trying to make him look stupid in front of Margaret, but both of them seemed far too excited to be playing any games.
“No, not really.”
“Think of it like a mesh,” Margaret said. “It’s a semipermeable membrane. That means things of a certain size can penetrate it, but things larger than that size cannot. It evolved to keep circulating blood separate from the extracellular fluid” — she paused, perhaps realizing she was going too far into detail — “to keep blood and other things separated from actual brain tissue. Blood can’t go through the barrier, but oxygen diffused from blood can. So if things are small enough, they can slide through the mesh. If they’re too big, they can’t. Follow me so far?”
Clarence nodded.
Tim held out his hands wide, like he was talking about the fish that got away.
“The hydra catalyst is too large to penetrate the barrier,” he said. “So to answer your question, the catalyst first works as an inoculant — if it’s already in your system before you are exposed to the infection, any crawlers produced will die before they can reach your brain. It makes you immune. And if you’ve already been infected but the crawlers have not yet reached your brain, the catalyst can kill off those crawlers. Meaning, if you get infected right now and we get this catalyst in your system within twenty-four hours, it will probably cure you.”
Clarence now understood their excitement. He was beginning to feel it himself.
“So if you take it soon enough, it is a cure,” he said. “What happens after the twenty-four hours?”
Tim shrugged. “The crawlers need about twenty-four hours to form, find your nervous system and reach your brain. If enough of them get in, they rework your brain into the cellulose-based structures we’ve seen. At that point, it’s too late.”
Clarence looked at Margaret. “But you said Walker had hydras in her brain. Hydras can get in there?”
Margaret nodded. “They can, following the same path the crawlers do. We don’t have much evidence to go on right now, but it seems possible the hydras travel to the brain instinctually, because they are so closely related to the crawlers. But there’s a difference — the hydras don’t seem to alter brain tissue. They’re just there.”
As far as cures went, alien organisms in the brain didn’t seem all that encouraging.
“Say the crawlers get to the brain first,” Clarence said. “They start changing everything around, and then the hydras get there. What happens then?”
Margaret glanced at Tim.
“The hydras probably keep secreting their catalyst,” he said. “Since they’re on the other side of the blood-brain barrier, and so are the crawlers, any crawlers exposed to the catalyst will die. Any cellulose-based structures probably dissolve.”
“Which means what to the host?”
“Death,” Tim said. “It means death.”
For a few minutes, Clarence had dared to hope that it was all over, that if some poor soul was infected, he or she could be saved with a shot or a pill. Life didn’t work that way, it seemed. Still, at least now there was something to fight with.
“Impressive work,” Clarence said. “So what happens next?”
“Tim goes to work on genetically sequencing the hydras,” Margaret said. “He isolates the genetic code that makes the catalyst, inserts that bit of code into the genome of his yeast, and the yeast produces the catalyst.”
That sounded impossible.
“Feely, you can really do that?”
Tim shrugged. “It’s how insulin is made for diabetics. The DNA that makes insulin is inserted into bacteria, the bacteria secrete the insulin, which is harvested and purified. When the bacteria reproduce, the subsequent generations have that same inserted DNA. Boom, you have a permanent, insulin-producing population.
“The basic technology is decades old. I’ve spent the last two years inserting crawler coding into my fast-growing yeast, so at this point it’s just plug-and-play. The only question is if my yeast will survive the new coding. If so, we’ll have Saccharomyces feely producing the catalyst inside of a few hours.”
A few hours? Clarence fought down his immediate reaction. He wasn’t going to get his hopes up this fast.
“Let’s hope you’re right,” he said. “What do you need to make this happen?”
Now Tim glanced at Margaret. She looked away, looked down.
“We need to make more hydras,” she said. “And there’s only one way to do that.”
HUMAN EXPERIMENTATION
Margaret had killed one of the hydras to analyze it. Another had died on its own; she assumed the last two surviving hydras couldn’t be far behind.
Time was running out.
Candice Walker was dead, as was everything inside of her. There were no more hydras to be had from her corpse.
Margaret entered the clear cell of Eric Edmund. She carried a small tray holding an alcohol swab and a syringe. She set the tray down on Edmund’s stomach. She had to remind herself that the man was brain-dead. He would never recover.
Edmund’s self, all that he had ever been, that was gone forever… but his body lived on. His heart pumped, his blood flowed, his cells divided. The human body was the hydras’ natural environment. There, hopefully, they would modify Edmund’s stem cells, make copies of themselves — they would replicate.
Margaret picked up the alcohol swab and wiped Edmund’s shoulder, cleaning her target area. She set the swab down and lifted the syringe. She stared at it through her visor. Just one CC of saline, and inside that fluid, a pair of passengers.
Only two left.
A slap on the glass. She turned to see Cantrell, staring at her, the lighter skin of his palms resting on the clear wall. His eyes… he looked like he was trying to control his anger.
“Doctor Montoya, what are you doing?” Cantrell smiled. He looked at the syringe. “Don’t you need permission for something like that?”
How could he know what she was doing? He didn’t know; he was just being difficult.
“Not your concern,” she said.
Cantrell frowned, spoke sweetly. “Awww, Doc, of course it is. He’s in the cell next to mine. What if something breaks? What you do to him could affect me.”
“You have nothing to worry about,” Margaret said. “You’re not infected, Cantrell.”
The smile returned. A chilling smile.
“Then let me out,” he said. “I keep testing negative… just let me out.”
Those eyes, so intense, so angry even though his voice sounded smooth and calm.
Why was she wasting time with him?
Only two left…
Margaret slid the needle into Edmund’s shoulder, then pushed the plunger all the way down. The saline emptied into his arm.