"We're looking at a steam rocket, Jeffer. Your invaders used a wood fire to heat the pipe. They ran water through the pipe and into the nozzle. Very inefficient, but in your peculiar environment they could move a tree with that. Slowly, of course."

"Why would they pick an injured tree?"

"Ask them. Did any survive?"

"One's dead. 'Five more are in bad shape. My wife won't let me near them. Wait a few days and see."

Clave and Anthon flew along the split in the great tank. They reached the cluster of black oblongs at the other end.

The Checker said, "Their wounds won't become infected. We didn't bring disease bacteria."

"What?"

"I was thinking aloud. I want to talk to your invaders. Take them on a tour, Jeffer, when they're ready. Show them the CARM."

"Kendy, I'm not sure I want them to know about you."

"I will observe only."

Clave and Anthon were flapping back to the CARM. They carried blackened cargo, and they no longer wore tethers. "Company coming," Jeffer said.

"Jeffer, you've concealed your contact with me from the rest of your tribe, haven't you?"

"I haven't mentioned it to them yet."

"I'll keep my silence while others are aboard. Play the game any way you like."

Clave and Anthon returned black with soot. They untied the now-clumsy wings, then wiggled in, pushing armfuls of blackened salvage ahead of them. Clave crowed, "I love it! It's really flying!"

"You never did like tide, did you, Clave? How's the leg?"

"It never gets any better." Clave flexed his right leg. The misshapen lump on his thighbone bulged beneath the skin and muscle. The compound fracture he'd suffered in Carther States had healed, but in the jungle there had been no tide to tell the bone to stop growing. "It feels like I strained it. If I have to fly any distance I'll use just one wing."

They set to mooring their loot along the walls. Two tremendous hooks, wood stiffened with metal. A meter's length of metal band with tiny teeth along one edge. A hardwood tube had kept its shape if not its strength; the remnants of charred plastic hose clung to one end.

"Weapons and tools," Clave said. 'There was wire twisted together like a harebrain net, but it was burned through in too many places. Nothing else worth taking except the pipe. We've got to have that pipe. We moored the lines to it, Jeffer. Let's pull it loose."

"It must be important, given that you've moored the CARM to a tree that's about to come apart. Why? Just because it's metal?"

"I've got a vague idea what this setup is for," Clave said. "We could duplicate everything except the pipe, in theory anyway. The pipe isn't just metal, it's starstuff, something out of the old science."

"Why do you say that?"