“Start where?” Ren demanded. His voice was steady.

“Start upon our attack. We brought little with us from our world, a few devices and scientific supplies; but for all this time since we arrived we have been manufacturing. It is difficult with so few materials at hand. But we are nearly ready. When I return now, we will start our last preparations.”

His voice rose to a sudden grim power, “We have prepared well for this conquest. It is a beautiful land down there; the women, so many of them like the princess, are very beautiful. The men, they are not like you two—they are already afraid of us. Some have seen us wandering near the cave entrances. They always run in terror.”

His chuckle had a horrible gloating. “They will be easy to kill. A swift attack upon the city; we are almost ready for it now!”

The boat at last came to the surface; the cover rolled back; the stars gleamed overhead as before, but the yellow moon had crossed the sky and was falling to the horizon behind them. Jim saw that they had come to the surface of a very small lake.

He could see all around its shore, a circular lake of black, cold-looking water. It lay unrippled, smooth as polished black stone, unbroken except as the boat’s gas bubbles rose, and by the V-shaped waves the boat left behind it.

Around the shore was a ring of mountains. Bleak, naked cliffs of rocks came down sheer to the water; behind them the mountains rose in tumbled, serrated ranks, naked crags and spires, snow-capped with yellow snow where the moonlight struck them.

Here in the remote mountain fastness, Talon had established his stronghold. This was an isolated lake, which a subterranean boat had been plowing.

At Jim’s elbow, Talon said, “These mountains seem to extend back endlessly. But I have another base already established on the Warm Sea, and from there I will make my attack. I have planned well.”

Ahead of them, in one small place the mountains were broken. A narrow canyon-like valley was open to the water, with a fringe of black-sand beach. Cave mouths showed along the sloping valley sides. Lights moved. The mouths of the caves were outlined by a green-white glare from within.