Carlo swallowed the last of the loaf quickly; Amanda sometimes came early for her shift, and it made him uncomfortable if she surprised him eating. He was about to return to the storeroom when a movement in the other cage caught his attention. He turned and pulled himself along the cross rope for a closer look.
Benigna remained attached to her plinth, but she was holding something in one of her hands. As Carlo approached she tried to conceal it, but it was too large to be hidden from view.
It was a stick, about half a stride long. One end tapered to a rough wedge; it must have been snapped off a slender branch. But Benigna’s half of the cage had been emptied of branches, and Benigno hadn’t breached the barred partition that separated him from his co. Carlo was stumped, but then he realized that Benigno must have thrown the improvised tool through a gap in the bars.
Carlo drew himself to the side for a better view. The skin on Benigna’s back was torn, as if she’d been trying to force the stick between the stone surface and her body. “You want to be free?” he said dully. She couldn’t reach her melded flesh with her fingers, however sharp she made the claws, but not only had she conceived of a better plan, she’d managed to communicate what she needed to her co.
Carlo fought to maintain his resolve. If he gave up now, where would that leave him? Watching Carla go blind? Murdering two of his own children? These animals had done nothing to deserve the hardship he was inflicting on them—but what had he or any of the travelers done to deserve their own plight?
“What’s happening?” Amanda had arrived.
Carlo explained what he’d surmised. “You’d better tranquilize her and take it away,” he said. They’d been entering the cage to put dead lizards within Benigna’s reach, without drugging her first, but he didn’t want anyone trying to wrest a sharpened stick out of her hand while she was conscious.
“So how will we stop them doing it again?”
“Build a proper wall, I suppose,” Carlo replied. “I’ll get a construction crew to put stone slabs across.”
Amanda hesitated. “Wouldn’t it be simpler just to let them breed?”
Carlo was tempted. “It would be simpler,” he agreed. “But I have another plan.”
He’d been turning it over in the back of his mind, unsure of its usefulness, but now Amanda had forced his hand. “I want to play Zosima’s tapes back into Benigna’s body,” he said. “I want to see what each of those messages does.”
“You mean… out of context? Without Benigno triggering her?” Amanda sounded skeptical.
“Yes.”
“What do you expect will happen?”
“I don’t know,” Carlo admitted. “But there’s no point trying to reconstruct the whole sequence—there was too much lost from one of the recordings. So I think it’s better to go the other way, and see if any of the individual signals have an effect on their own.”
“What if that just cripples her?” Amanda protested. “If it goes wrong the way your finger did, it’s not going to be fixed by an amputation—and she certainly won’t be able to breed.”
“We have to take that chance,” Carlo said. “How else are we going to decipher this language? We have to study something more complicated than a twirling finger—but we’re never going to make sense of the fission process without breaking it down into smaller parts.”
“It’s your decision,” Amanda said. “I’d better—” She gestured toward Benigna.
Carlo moved aside and let her into the equipment hatch so she could dispense a dose of tranquilizer through the plinth.
“Silvano’s going to make trouble for you with the Council,” Carlo said. “He was counting on your support, and now he thinks you’ve turned against him.”
Carla hummed wearily. “Why does he have to take everything personally? If this works out, we’ll have a better chance than ever of reclaiming the engine feeds. He wants space for new farms, doesn’t he? I thought politics was all about the ends.”
Carlo dragged himself over to the lamp and rescued the front room from its drab moss-light. “Politics is about people’s feelings.”
“And exploiting them for your own ends,” Carla replied.
Carlo was still annoyed with Silvano, but he wasn’t feeling quite so cynical. “For three generations, we’ve had to make do with what we carried with us from the home world,” he said. “When the Object came along, everyone expected something from it. Silvano was hoping we could farm there, and he’s already had to give up on that. A universal liberator sounds dangerous—but the idea of mastering it still makes us feel powerful. Now you want everyone to forget about the Object and just trust you to pull energy out of thin air.”
“No one has to take this on trust,” Carla replied. “If it works, it will work right in front of their eyes.”
Carlo said, “But they still need to trust you that it’s worth the resources to build this thing you want to put before their eyes.”
“So do you believe there’s any chance that it will work?” Carla didn’t seem hurt by his lack of confidence; if anything, she sounded glad to have someone skeptical whom she could interrogate on the matter.
Carlo was honest with her. “I don’t know. All this shuffling of luxagens between energy levels sounds a bit like sleight of hand.”
“The light source we’ve already made was all about shuffling luxagens between energy levels,” Carla protested. “The Council had no problem approving that idea.”
“Because you shine a stonking great sunstone lamp on it!” Carlo replied. “It doesn’t offend anyone’s common sense to think that you can put light in and get light out.”
“All right.” Carla thought for a while. “Forget about the details of the device, then. Just look at what it claims to do.”
She made a quick sketch on her chest.
“The Peerless has a certain energy-momentum vector before we use this device,” she said. “It’s just an arrow whose length is the mass of the whole mountain, and we draw it vertically in a reference frame in which we start out at rest.”
“Right.” Carlo wasn’t so tired that he couldn’t follow that much.
“The photon rocket emits a pulse of light,” Carla continued. “Ultraviolet, preferably, so it’s moving rapidly and its energy-momentum vector is a long way from vertical. To obey the conservation laws, the total energy-momentum has to be the same, before and after that pulse is emitted. Before, there’s just the original energy-momentum of the Peerless: the vertical arrow. After the pulse is emitted, there’s the light’s vector, plus the new vector for the Peerless, whatever that might be. The sum of those last two vectors has to equal the first, so if you join up their arrows base to tip they form a closed triangle with the original vector.”
She paused inquiringly. “I’m still with you,” Carlo said.
“If the rocket had no effect on the mountain other than giving it a push,” she continued, “the new vector would need to have exactly the same length as before: the same mass. That would be ideal—but I’m not even claiming to be able to do that! Instead, if we allow for some waste heat raising the temperature of the Peerless, the extra thermal energy lowers the mass of the mountain, very slightly. But even that doesn’t ruin the geometry—there are still vectors for the light and the accelerated mountain that add up, exactly as they need to.”
Carlo gazed at the closed triangle on her chest. “I can see that it’s not physically impossible, in those terms,” he conceded. “But everything else that makes light needs some kind of fuel, some kind of input.” He gestured at the walls. “Even moss has to have rock to feed on.”