Slick. I wondered if our feddies had ever suspected Iranu junior of following in his father’s footsteps. Probably… but junior was tied so close to the Freep government he’d have diplomatic immunity. Anyway, Maya must have done most of the fieldwork; Iranu just dropped by now and then to see how she was doing.

And how was she doing? With all their undercover digging, had Iranu and Cuttack turned up anything useful? Or were they just flouncing around in the dirt, without finding bugger-all?

Gingerly I stepped past the Greenstrider robots and lifted the torch-wand to light the rest of the room. It showed more robot watermelons on ostrich legs, and assorted machine boxes — computers maybe, or communication transceivers, food synthesizers, air conditioners. How can you ever tell? One box of wires looks much like another… and these had been rusting in a hot humid climate for three thousand years.

No, not that long — this room had been sealed hermetically for a long time, till an earthquake opened that breach in the wall. It explained why I recognized this stuff as machinery, unlike the moldering lumps in the outer room. It’d taken longer for microbes and humidity to get in. Even so, every exposed surface here was covered with corrosion; I doubted anything was still in working order.

Festina had her Bumbler out, running its scanner up and down a Greenstrider robot. "Interesting," she murmured.

"What?"

"See here?" She pointed to a flap of green skin folded back from the creature’s chest to reveal metal beneath. "The edges are clean," she said, "and the metal has practically no rust."

I held the torch-wand close so I could see for myself. She was right — the skin had been sliced away with a knife. Underneath, the robot’s innards had a passable gleam. "Probably the work of our bold archaeologists," I said, "cutting a hole to peek inside."

"But here…" Festina squatted and aimed her finger at the point where the robot’s left leg joined its torso. "This damage is much more ragged. And the metal’s been exposed to air a lot longer."

I crouched and looked. The scaly ostrich skin had been eaten away, eroded to shreds; and the armatures beneath were speckly brown with rust. "Sure," I agreed, "this damage is older. But what does that mean? The natural decay process had to start somewhere. This is just where the skin flaked off first."

"It doesn’t look like natural decay to me." Festina fiddled with the Bumbler controls; the image on the machine’s vidscreen ballooned through several powers of magnification. "See around the edges there? A rim of white plastic. There used to be a plastic sheath just under the skin, like a protective wrap around the metal flexors. Something chewed away most of the plastic, and bared what was underneath."

"Acid?" I asked.

She shook her head. "Then I’d expect to see melting, and there’s nothing like that. This looks more… eaten."

"Demoth has bacteria that can break down some types of plastic," I told her.

"But there’s still some plastic left," she replied, moving the Bumbler’s scanner up and down the robot’s leg. "Once a bacterial colony begins consuming a particular substance, why would they stop? No. To me, this looks like an entrance hole. Something ate through the skin, then consumed just enough of the plastic sheath to get into the robot’s guts."

"I assume you don’t mean pesky jungle insects?"

"Most likely a coordinated nano attack, specifically designed to disable this type of robot."

She grabbed the Bumbler’s scanner and gave a yank. The scanner pulled out of the Bumbler’s body, trailing behind a fiber-steel umbilical cord… like a thumb-sized glass eye on a flexible tether. Festina jammed the eye through the break in the robot’s skin. "Yes," she said, "the circuits are a real mess in there. Diced. Wire salad."

"So nanites bit their way in, then chewed up the robot’s guts? Why?"

"It was a weapon, Faye." She pulled the scanner out of the robot and stood up. "Like I said, Greenstrider colonies had a habit of disintegrating into civil war. Faction against faction. They’d start off targeting each other’s machinery, just like this — the League of Peoples doesn’t mind if you corrode the guts out of mindless robots. But how long before tactics accelerated into something uglier?"

I looked around the room: the unmoving robots, the rusting machines. Shut down by enemy nano? And what happened when the nanites destroyed other equipment… food synthesizers, say. Could Greenstriders eat our local flora and fauna? Or did the war against each other’s machinery send the colonists spiraling down to slow starvation?

Next question: how far would starving people go for revenge on their enemies? Bombs? Poison gas?

Germ warfare?

Maybe.

And when the war heated up, some Greenstriders would hide from their enemies. Huddle down in places like this, where they’d hope they were safe from nanites, armies, whatever their opponents might throw at them. Underground complexes in Mummichog, in Sallysweet River, all over Demoth.

We’d thought these were ancient mines; and some probably started out that way. But in the end… they’d become military bunkers.

PINNED BUTTERFLY

The other Greenstrider robots had the same kind of damage: entry wounds where the legs met the torso, minced machinery inside. I guess the point of attack got chosen because it was especially vulnerable… or maybe just handy and close to important control circuits. No way to tell now — the robots had all been gutted too badly to reconstruct how they used to work.

And speaking of reconstruction… where did that leave Maya and Iranu? These robots looked too wrecked to be salvageable. What here could gladden the heart of a greedy archaeologist?

I moved around the room, giving each machine the once-over. A few rusty boxes had got opened and partly dismantled, half-rotted circuit boards laid out on the floor: Maya and Iranu must have been seeing what they could find. They’d done the most work on something that looked like a control console — a flat surface with bumps and lumps that might have been eroded push buttons, plus dirty plates of clear plastic that were probably screen readouts. Maya and Iranu had pried off two access panels under the console and gone fishing inside; you could see gaps where they’d removed bits and pieces for examination. But everything I saw looked too rust-eaten to be functional. If the archaeologists learned much from what they found, they must be rare good at their jobs.

Two times circling the room with the torch in my hand… and only then did it click back into my head that there were no doors anywhere. We’d clambered in through that spot where the wall crumbled; but that definitely wasn’t a real entranceway. As far as I could tell, the room had been totally sealed up with four mock-granite walls… and that didn’t make sense, did it?

"Festina-girl," I called, "time to give the Bumbler another workout. These walls look too good to be true."

They were. The Bumbler found two patches of wall whose temperature ran a titch warmer than their surroundings: both patches almost straight-edged rectangular, three meters wide, stretching from floor to ceiling. One patch was plunk in the middle of the wall between this room and the outside tunnel; the other was at the rear of the chamber.

"All right," Festina said. "So two sections of wall aren’t the same as the rest. Yes, they’re probably doors. But how do we get them open? Maybe once upon a time they unlocked at the flick of a switch… but every switch in the place is rusted clean through."

"O ye of little faith," I told her. "When you’ve got the right friends, who needs switches?"

My thoughts: the Greenstriders used nano weapons. So they probably used nano for other things too — like doors. The doorways could be like the windows in my office: made to look solid, but the nanites would let you pass if you had proper authorization.