Dr. Alison Collingwood had been hard at work for ten straight hours when she confirmed it. Bleary eyed with exhaustion, suffering cricks and cramps in her neck and back, she straightened up with a soft groan and ran both hands through her hair, dragging the lank mess back from her face. It had taken the combined computing power of two Bolos, Bessany Weyman's xeno-ecological genetic testing equipment, added to her own, blood and tissue samples from Chilaili and samples gathered by the Bolo at Rustenberg from Lieutenant Commander Lundquist and from the carcasses of dead birds which comprised the Tersae's ancestral stock, plus samples of the neurotoxin put through tests she had requested Senator to conduct; but she finally had the answer.
Stumbling slightly over her own feet, she told her assistant, "Good work, Arnie. Fabulous work," and emerged from the biochem lab where they'd been closeted for so long. When she stepped outside, Alison was surprised by the ominously clear daylight air. The sky was crystalline, the sunlight so bright it hurt, reflected in diamond-point sparkles off the snow. The Bolo, parked just outside the lab, greeted her at once.
"Good afternoon, Dr. Collingwood. Do you have news?"
She nodded wearily. "We've got it, Rapier. Humans aren't at risk."
A hatch opened high overhead and Lieutenant Colonel Weyman appeared, moving fast as he skinned down the ladder without touching the rungs. Bessany Weyman and the rest of the station's personnel—those not confined to the infirmary—came running through the snow, alerted by the Bolo's booming voice. Chilaili, too, appeared from somewhere behind the Bolo.
"You're certain?" the Bolo's commander asked the moment he reached the ground.
"Yes. Completely. The damned thing's diabolical. And so is whoever developed it. Bessany, you were right. Not only was that neurotoxin created specifically to kill the Tersae, it had to be gengineered at the same time the Tersae were developed."
"What do you mean?" Colonel Weyman asked with a frown.
Alison thinned her lips. "The neurotoxin attacks a specific neuropeptide receptor site and triggers a chain reaction through the cells, killing the host horribly within minutes. Humans don't have that particular neuropeptide or its receptor sites. When I asked Senator to test the neurotoxin on tissue from live, uninfected ancestral stock, the stuff invaded within seconds. When exposed to human tissue, the stuff was completely inert. No molecular action at all."
"That doesn't necessarily mean it was gengineered specifically for the Tersae. Any number of wild species on Thule could be affected."
She shook her head. "No, they wouldn't. Bessany's taken specimens from a whole range of species similar to the Tersae over the last three months. Only one of them has this neurotransmitter."
Bessany scowled. "That's the one they used as ancestral stock then." She glanced at her tall brother-in-law. "If Alison didn't find that neuropeptide in the other samples, it's because it's not there. There are biochemicals in muscles that aren't found in the gut, for example, and there are neuropeptides unique to the brain. So for every species I tranked with the dart gun, I took bone and marrow samples, brain tissue, muscle and gut samples. I scraped talons and claws, sampled myelin sheathes, and clipped small nerve samples. I was thorough."
Alison nodded. "So was I. Believe me, I was. I tested every one of those samples, checked and triple checked the results, had both Bolos do the same. Humans are not at risk from this stuff."
Tension drained visibly as Lieutenant Colonel Weyman rubbed the bridge of his nose. "Thank God," he said quietly. "Good work, Dr. Collingwood. You too," he nodded toward her assistant, who had come stumbling out of the lab to join them. "All right, the first thing we do is tell the refugees from Rustenberg they can go home, get them out of this freezing weather."
"Those refugees may not be at risk," Bessany said bleakly, "but Chilaili is. And Sooleawa. And every other Tersae who might be persuaded to switch allegiance. Given the way this war's going, with the clans losing so heavily, the Ones Above may decide to destroy them, just to keep us from getting our hands on any live prisoners. If we don't help them, the Tersae don't have a prayer. And everyone at this station owes Chilaili that much, at least: a simple shot at survival."
"I agree, completely," the Bolo's commander frowned, "but I don't see any way to stop that neurotoxin, if the Ones Above decide to send the signal that releases it. Unless . . ." he paused, a startled look blossoming in his eyes.
"What?" Bessany asked urgently.
"We can't stop them from releasing the stuff without some way to clog the release valve so it can't disperse, and even that's no guarantee that some of it won't get out. But what if we could block their neuropeptide receptor sites?"
Alison's jaw dropped, even as she kicked herself for not thinking of it first. "Good God. Develop an inert analog?"
He nodded. "Exactly. Can you?"
"I don't know," Alison said, a trifle breathlessly. "I don't know, but it's worth trying."
"There's still a delivery problem," he mused, brows hooked downward. "We'd have to get it into their living quarters, which won't be easy."
"There's not a problem with Icewing Clan," Bessany insisted. "Chilaili could take it right into the nest."
Everyone swung around to look at the Tersae.
"I do not understand," Chilaili said. "What is this 'analog' you speak of making?"
Bessany answered. "We want to create a substance that would prevent the weapon in the Oracle from harming you. Like an antidote to poison. Even if the Oracle released the poison, if you had breathed the substance we created first, the poison wouldn't harm you." She glanced at Alison. "How far in advance would we need to release the analog, to protect them?"
Alison held up her hands. "I don't know. Best guess, an hour? Unless those tissues are saturated, the neurotoxin would get through."
Lieutenant Colonel Weyman nodded. "I'll talk to Rapier about possible delivery systems we can cobble together. If we can protect your clan," he asked Chilaili, "can you convince them to renounce allegiance to the Ones Above? To try an alliance with humans? Or at least call off the attacks on Seta Point and Eisenbrucke?"
Alien eyes blinked in the harsh sunlight. "We will risk much, to save the eggs from further tampering. But I think the Council would have to witness a direct attempt by the Ones Above to kill us, to convince them we should seek alliance with humans."
The Bolo spoke up. "I have an idea about that, Commander. I am convinced the Oracles are both the source of the neurotoxin and the means by which to effect a reversal in the loyalties of the Tersae. If Dr. Collingwood is able to develop a compound to block the neuropeptide receptors, then we have a way of preserving the Tersae. I believe I have come up with a way to persuade Icewing Clan to transfer its loyalties. If Chilaili agrees to try my experiment with her clan, and if you can persuade General McIntyre that we have much to gain, with relatively little risk to human personnel, I would suggest conducting a trial run the moment Dr. Collingwood's analog is ready."
"What, exactly, do you have in mind?"
"I intend," the Bolo said with just a trace of smugness in his voice, "to subvert the Oracles . . ."