The bath had fixed my body, but my mind still felt drained. Maybe my mind just needed time to catch up. I flexed my hands, no longer sensing that exhausted feeling.

  Gorthak stood near a door with two Tog guards. Philip sat in a corner. Rhea paced in front of a large wall map of Tellus. The map was ancient, its colors faded, but I could make out old countries, none of them were familiar.

  “Do you want to know what I know?” she said, not looking at me. “Do you want to know why Gorthak is upset with me?”

  Oh, she was going to tell me after all.

  “Yeah, let’s hear it,” I said.

  She turned to me, and she looked desperate—I had no idea why.

  “The Atomic Brains run atmospheric processors, scrubbers, if you will,” she said. “They’re all over the planet, many of them deep underground, filtering radiation and toxins from the ground and air.”

  I raised my eyebrows. That was interesting, and this world made a little more sense, at least, as to why there was still life here.

  “Scrubbers—always she speaks of scrubbers,” Gorthak said, clearly having heard this before.

  Rhea glared at the big Tog. “Yes, you—” She swallowed down whatever she’d been about to say. Maybe it would have been, “You idiot.” Then she started over. “Don’t you understand? Without the scrubbers we die. All of us, gone.”

  “Bah!” Gorthak said, waving a big hand in dismissal.

  “It took me time to understand all this,” Rhea said. “It didn’t all come at once. Anyway, I’ve come to believe that forty-seven stations are still online. They’re the only reason anyone can breathe on this war-plagued planet. The nuclear war poisoned everything. The background radiation alone would kill us without the constant scrubbing.”

  “The air was breathable before the machines,” Gorthak said. “It will be breathable after.”

  Rhea shook her head. “That was before hundreds of warheads detonated, before reactor meltdowns everywhere. And that was well before the chemical weapons. The planet is toxic now, Gorthak. It has been that way for possibly three hundred years. If you need something to pray about, pray that the scrubbers keep working.”

  “How toxic are we talking about?” I asked.

  She pulled out a handheld device. “Right now, with scrubbing we’re living on the edge but surviving. Without it we would have biosphere collapse within two years.”

  “You lie,” Gorthak said.

  She turned to him. “I’m a lot of things, but I’m not a liar about this.” Rhea put the device away. “I’ve spent years studying the old records, the environmental data. The machines didn’t just start a war—they also made themselves indispensable. Maybe on purpose, maybe by accident, but the result is the same.”

  Philip shifted in his corner but said nothing. I knew he’d been taking this in with interest. I wondered what he was thinking.

  “So if someone uses shutdown codes on the Atomic Brains like Gorthak thinks you can…” I said, trying to prod her.

  “Then everyone dies,” said Rhea. “And that wouldn’t happen in some distant future. Within two years, this planet is a complete dead rock. Any recovery would demand massive reconstruction and atmospheric converters.” She looked at Gorthak. “That’s why I won’t give you the codes. Even if you could fight your way to the Atomic Minds, you’d be committing suicide and taking every living thing with you.”

  “Then we can never be free,” Gorthak said, his voice hollow.

  “I didn’t say that. I said the shutdown codes aren’t the answer.”

  “What is?” I asked.

  Rhea shrugged. “I don’t know. I’ve been trying to figure that out for years. The combat and maintenance systems are integrated. You can’t separate them. It’s like…” She paused, maybe searching for an analogy. “It’s like trying to remove someone’s ability to fight while keeping their ability to breathe. They use the same core systems, see.”

  The room grew quieter, maybe everyone thinking about what she said.

  I could feel the weight of it, the impossible trap these people were in. Fight the machines and die in battle, or destroy them and die from the poisoned air. What horrible choices.

  “The Steel Mother,” Gorthak said finally. “Does she control all of it?”

  “That’s hard to say,” Rhea answered. “I doubt it, but who knows. If that were true, though, then she would coordinate it all from the Deep Black.”

  “Where’s that?” I asked.

  “From what I’ve been able to glean, it’s a deep subterranean place past the machine factories,” Rhea said. “The Atomic Brains have taken everything deep in order to protect themselves from thermonuclear missile strikes.” Rhea looked tired suddenly. “From what I’ve learned, no human or Tog who ever went that deep has ever come back up again.”

  Gorthak snorted and turned to leave. “Then we have nothing more to discuss. This was all a waste.”

  “Wait,” I said. “There has to be another way.”

  “There isn’t,” Rhea said. “Trust me. I’ve looked at every possibility. The only choices are slow death by robot or quick death by poisoning.”

  I kept thinking about what she’d said. The systems were integrated like breathing and fighting in the same body. There had to be a way to separate them, or at least modify them. I glanced at Philip, who was still unusually quiet. Did he know something? With Philip, he usually did.

  I turned back to Rhea. “Thank you for explaining this. It all makes a lot more sense.”

  She studied me. “You’re thinking something.”

  I shrugged. “Maybe I am. But right now I need to think about it more.”

  Gorthak grunted. “Think all you want, Plasma-singer. But thinking won’t change the truth. We’re all dead anyway, just a matter of how and when.”

  That was a sobering thought. But was the Tog chief right?

  -28-

  There was silence again as we all absorbed this.

  Then I heard distant thumps, like someone hammering on pipes far away. I heard sharp cracks echoing down through the tunnels after that.

  Gorthak’s head snapped up. “That from above.”

  There was another round of sharp cracks. Could that be pulse rifle fire? It lasted longer this time. Afterward, very faintly, I heard screaming.

  “We under attack,” one of his guards said, stating the obvious.

  Gorthak was already moving. “Everyone to main chamber. Go now!”

  The Tog warriors rushed out, their heavy feet pounding on the tunnel floor. They moved fast for such big guys, tusks gleaming in the light as they charged toward the sounds of combat. In seconds, they’d vanished around a bend, leaving us behind.

  I grabbed the pulse rifle I’d taken earlier and started after them. Philip hung back, looking for somewhere to hide, it seemed to me. Rhea stood frozen, clutching her scanner.

  “Come on,” I said to both of them.

  “This isn’t our fight,” Philip said.

  “Everything down here is our fight.” I started jogging up the tunnel.

  More explosions echoed through the tunnels. The lights flickered and died, then came back at half strength. Whatever was happening up there was big.

  Rhea hurried after me, soon falling in step. Philip reluctantly followed from further back.

  “Slow down,” the Homo habilis called.

  Rhea and I halted.

  Philip walked in his leisurely manner.

  “Hurry your butt up,” I said, “or I’m leaving you behind.”

  He increased his pace, but it was still too slow.

  Finally, however, we all started together. We made it maybe fifty meters from the chamber when the wall to our left exploded with a roar.

  It wasn’t cracked or broken—it exploded. Chunks of concrete sprayed across the tunnel as a walker burst through like something out of a nightmare. Its circular buzzsaw blade was already spinning, filling the air with that high-pitched whine I hated.

  I brought the pulse rifle up, but the walker was faster than the ones I’d fought before. Its saw swept the rifle aside, cutting off most of the barrel. For some reason, that caused the power pack to detonate, throwing me backward hard.

  Two more walkers came through the hole, their red sensors sweeping the tunnel. One locked onto Rhea, the other onto Philip.

  I rolled to my feet and activated the baan as I tore it off my belt. I felt sluggish and stunned from the blast, but I had no more time to think about it.

  The blue energy blade hummed to life as the first walker rushed me. I brought the blade up, catching its saw arm at the joint. The limb fell away in a shower of sparks, but the walker didn’t slow down. Its other arm punched toward my chest.

  I twisted aside. Then I brought the baan around in a horizontal arc, taking the walker’s head off at the neck. It toppled forward, nearly pinning me before I dove clear.

  The second walker had Philip.

  The little Homo habilis was shrieking like a monkey as the machine lifted him by his EVA suit; mechanical fingers crushed the material. Philip’s feet kicked uselessly in the air.

  “Bayard!” he screamed.

  I started toward them, but the third walker opened fire with its pulse rifle. The beam seared past my head, so close I smelled burning hair. I hit the ground, rolled behind the headless walker’s corpse as more shots punched into it.

  “Help him!” Rhea shouted. She’d picked up a chunk of concrete and hurled it at the walker holding Philip. It bounced off harmlessly.

  The walker with Philip was backing toward the hole they had made. It must be taking him somewhere. I couldn’t let that happen—even Philip didn’t deserve whatever the machines had planned.

  I came up running, zigzagging as the third walker tried to track me. One shot nicked my shoulder, spinning me around. The leather of my jacket was smoking, the skin underneath already blistering. But I kept moving, closing the distance.

  The walker holding Philip was almost at the hole. I wasn’t going to make it.

  Then Rhea did something incredibly brave and stupid. She ran straight at the shooting walker, waving her arms and screaming. It swiveled toward her, pulse rifle rising.

  “No!” I shouted.

  The walker fired. The pulse beam took Rhea in the chest. She looked down at the smoking hole, seemingly surprised more than anything else. Then her legs folded and she went down.

  But her distraction had worked. I reached the walker holding Philip and brought the baan down in a vicious overhand strike. The blade carved through its shoulder, severing the arm holding Philip. We both tumbled to the ground.

  The shooting walker spun back toward us. Philip scrambled behind me as I brought the baan up in a desperate block.

  The pulse beam hit something—not us, but the floor between us. The ancient concrete, possibly already weakened by who-knew-how-many years and by the walker’s explosive entrance, gave way.

  The floor disappeared beneath us.

  I had just enough time to see Rhea’s body, to see her eyes staring at nothing, before Philip and I and the damaged walker all fell through into darkness.

  We dropped maybe three levels—ten meters of rusted pipes and broken concrete flashing past. Then we hit water. It was cold and black, and it rushed into my nose and mouth. The impact knocked the baan from my hand. I felt it slip away into the depths as it hissed.

  I kicked toward what I hoped was the surface and came up gasping. Emergency lights in the ceiling gave just enough illumination to see we were in some kind of flooded maintenance area. Pipes as thick as trees ran along the walls. The water came up to my chest.

  Philip surfaced beside me, coughing and spitting. “I can’t… swim well.”

  I grabbed his arm, keeping him steady. The walker that had fallen with us was sparking and twitching as it sank, electricity arcing across the water. We both jerked as minor shocks ran through us, but then the thing must have shorted out and gone dark.

  Above, I could see the hole we’d fallen through. Red eyes appeared at the edge. More walkers must have come through the hole in the wall and were looking down at us.

  “Move,” I hissed, before realizing Philip’s feet didn’t touch the bottom.

  I dragged Philip toward the nearest cover as pulse beams started raining down on us. The water around us hissed and steamed where the shots hit. We ducked behind a massive pipe just as a beam nearly took Philip’s head off.

  The shooting continued for another few seconds, then stopped. I could hear mechanical sounds above. The walkers were doing something.

  “We need to get out of here,” I said.

  “What a brilliant observation,” Philip gasped. “And how do you propose we do that?”

  The flooded chamber stretched out into darkness. There was no visible way up, but I could see where the water flowed deeper into the complex. There was a tunnel at the far end, partially submerged.

  “We go forward,” I said.

  “You mean toward the Deep Black? Are you insane?”

  “Would you rather wait for the walkers to come down here and finish us?”

  Philip looked up at the hole where the red eyes had vanished, then at the dark tunnel ahead. “Rhea’s dead.”

  “I know,” I said.

  “She had knowledge and understanding of this place.”

  “I get it.”

  “We’re going to die down here,” he said.

  Instead of arguing, I dove into the water and searched with my hands. I came up gasping and immediately went down again. My hand grasped the baan. I came up, gasping for air. I wondered if the baan had a failsafe for water, automatically shutting down. I clipped it back onto my belt.

  Then I started wading toward the tunnel, pulling Philip along.

  The water was cold and smelled of rust and old chemicals. Every step stirred up sediment that had probably been undisturbed for decades. Behind us, I could hear the walkers: metal feet on metal rungs. They’d found a way down, I guess.

  We reached the tunnel and I had to duck to enter. The ceiling was low, with maybe a foot of airspace above the water. Philip made a frightened noise but didn’t complain as usual. What choice did either of us have?

  The tunnel went on and on, sometimes opening into larger flooded rooms, sometimes narrowing so much we had to turn sideways. The emergency lights were sporadic now, leaving long stretches of absolute darkness where I had to feel my way forward.

  “I can’t see anything,” Philip whimpered.

  “Don’t worry about it.”

  “What if there’s something in the water?”

  “Then we deal with it.”

  “That’s not reassuring.”

  “I wasn’t trying to be.”

  His whining was making me angry.

  We waded for what felt like hours but was probably twenty minutes at most. The sounds of pursuit had faded. Maybe the walkers couldn’t follow through the flooded sections, or maybe they knew where we were heading and didn’t need to chase us as they would meet us there.

  Finally, the tunnel opened into a larger space again. The water was shallower, only knee-deep. Ancient machinery lined the walls: generators maybe, or pumps, all dead and rusted. A metal stairway led up out of the water to a platform and a heavy door.

  I waded there and let go of Philip. Then I climbed the stairs and tried the heavy door—it was locked.

  “Now what do we do?” Philip asked in his whiny voice. He’d followed me up.

  I unhooked the baan.

  “It’s probably broken now,” he said.

  I pressed the activation switch and the baan shivered in my hand. I did it again; it shook harder, and then the plasma blade appeared.

  “Are you ready?” I asked.

  “No,” he said.

  “Good,” I said, starting to carve a hole into the heavy door.

  -29-

  The baan’s energy blade had carved through the heavy door like cutting through warm butter, leaving edges that glowed orange and slowly cooled. I pushed the cut with my boot, keeping the baan activated and ready as the thick metal clanged against the floor.

  We both waited, listening, wondering if anyone who heard the clang would come to investigate.

  Finally, when no one did, I started forward across the cooling metal. I entered the beginning of a large stairwell that went down but not up. This was one of the terminus points then.

  Philip stepped from behind me, his flashlight beam stabbing into the darkness below.

  “Wow,” I said, seeing it better now.

  We stood at the railing edge of a stairwell that plunged into blackness. The width of the stairwell was maybe forty feet across. The part we could see was metal stairs that hugged the inner wall, spiraling down with landings every twenty feet. Well, we saw two landings. The beam didn’t go far enough to see more. The construction was industrial brutalism: thick steel beams with riveted plates, everything looking as if it were built to last centuries, which it no doubt had been.

  Philip leaned over the railing and played his light farther down. Darkness swallowed the beam after a time.

  “How far does this go down?” I asked, my voice echoing.

  “I couldn’t possibly know,” Philip said.

  I glanced at him, wondering why he’d said it like that.

  “Is that true?” I said. “The Institute has studied Tellus, and it seems particularly Ploor. You knew where that command center was, and you knew your little device would open the blast door. I’m betting you know all about this stairwell as well. And you know what, I want to hear it.”

  Philip was quiet for a moment, and then shrugged. “From our analysis of similar structures, the machine cores are typically located between one hundred and one hundred and fifty stories below surface level.”

  “Machine cores?” I asked.

  “The Synthetic Minds,” he said.

  I nodded. “When you say stories, you mean like regular floors, like ten feet each?”

  “That seems right.”

  “That’s over a thousand feet down then.”

  “And thus makes any possibility of descent impossible for you and me.”

  I frowned. Who’d said anything about going down? Was he using reverse psychology on me?