We moved on through the forest, searching for the tiny road signs of the Vepajans, which Kamlot had described to me as well as explaining the location in which they are always placed. The sign consists of a long, sharp nail with a flat head bearing a number in relief. These nails are driven into trees at a uniform height from the ground. They are difficult to find, but it is necessary to have them so, lest the enemies of the Vepajans find and remove them, or utilize them in their search for the cities of the latter. The method of the application of these signs to the requirements of the Vepajans is clever. They would really be of little value to any but a Vepajan as guide posts, yet each nail tells a remarkable story to the initiated; briefly it tells him precisely where he is on the island that comprises the kingdom of Mintep, the jong. Each nail is placed in position by a surveying party and its exact location is indicated on a map of the island, together with the number on the head of the nail. Before a Vepajan is permitted to descend to the ground alone, or to lead others there, he must memorize the location of every sign nail in Vepaja. Kamlot had done so. He told me that if we could find but a single nail he would immediately know the direction of and distance to those on either side of it, our exact position upon the island, and the location of the city; but he admitted that we might wander a long time before we discovered a single nail. The forest was monotonously changeless. There were trees of several species, some with branches that trailed the ground, others bare of branches for hundreds of feet from their bases. There were boles as smooth as glass and as straight as a ship’s mast, without a single branch as far up as the eye could see. Kamlot told me that the foliage of these grew in a single enormous tuft far up among the clouds. I asked him if he had ever been up there, and he said he had climbed, he believed, to the top of the tallest tree, but that he had nearly frozen to death in the attempt. “We get our water supply from these trees,” he remarked. “They drink in the water vapor among the clouds and carry it down to their roots. They are unlike any other tree. A central, porous core carries the water from the clouds to the roots, from whence it rises again in the form of sap that carries the tree’s food upward from the ground. By tapping one of these trees anywhere you may obtain a copious supply of clear, cool water—a fortunate provision of—” “Something is coming, Kamlot,” I interrupted. “Do you hear it?” He listened intently for a moment. “Yes,” he replied. “We had better take to a tree, at least until we see what it is.”