“I will climb that tree, the tall one,” Nenne said. “From the upper limbs I can see over the barrier, see what lies behind it.”

He was a good climber, had climbed the valley wall many times, and this was much easier. Small twigs and leaves rained down as he swarmed up the wide branches. He stayed just a moment, then returned as quickly as he had gone.

“Nothing,” he said, his voice puzzled. “There is simply sand inside. Empty, the creatures who were there yesterday are gone. Unless they are buried in the sand—they are gone.”

“We will go to the place you watched from before, close to the killing area,” Kerrick said, taking up his bow while Nenne swung the leather bag to his shoulder.

The corpse of the deer was there, now buzzing with flies, beyond it the green wall studded with the dead creatures. Kerrick flexed his bow and selected an arrow while Nenne opened the bag.

Kerrick carefully tied the strip of cloth around his arrow, then dripped the charadis oil onto it from the skin container. Nenne was hunched over to keep off the breeze while he scratched fire from the stones. He added dry twigs until small flames were crackling in the pit in the sand. Kerrick stood, half-drew his bow with the arrow he had prepared, bent and touched the oil-soaked rag to the flames. It caught fire, the flames invisible in the sunlight but the dark smoke clearly seen. Then he stood, drew the arrow far back, aimed high in the air—and released it.

It rose in a great arc and dropped into the green barrier. They could see it there, where it had impaled a leaf, smoking slightly. When the smoking died away Kerrick sent another burning arrow after the first, then another and another. The results each time were the same.

“They have learned,” he said, his voice grim as death. “They know about fire now. We won’t be able to burn them out a second time.”

Nenne tapped his forehead with puzzlement. “None of this do I understand.”

“I do. They have a base on land, one we cannot attack or burn.”

“We can use arrows and spears; they will not be safe behind this barrier.”

“This one, this size, I agree that they would not be safe. But if they grow a larger one they could retreat behind it at night—out of range.”

“These murgu do strange things,” Nenne said, spitting with distaste in the direction of the green wall.

“They do—because they do not think as we do. But I know them, I should be able to understand what they are doing. I must think hard about it. This has not been done without meaning—and I should be able to understand the reason for it being here. Let us get closer.”

“That is certain death.”

“For animals, yes. Just go carefully.”