At last the trail forked upward from the stream, following a narrow ledge of rock along the canyon wall. The footprints of the slain Venusian now were wide apart and deeply imprinted in the sand, indicating that the creature had run rapidly down the path. "He probably spotted our ship landing and headed toward us right away," muttered Arlen. "His presence outside the craft may have been what made Gheal so uneasy yesterday. Gheal sensed an enemy near at hand." But this didn't seem to be the answer, either. Beyond the next curve the canyon walls slid back and the ledge widened into a gentle slope leading to the top of the canyon. As Arlen climbed over the rim he found himself on a plateau. It was dark now, but the place was lighted by a huge campfire not far away. Huddled around the campfire were four figures. In the still air of the night, Arlen heard guttural grunts of Venusians and above these tones he heard the sharp voice of Harry Renzu issuing commands to these alien beasts. Arlen crept forward and concealed himself behind a rock. There were three Venusians. He saw something else, too. McFerson, his head swathed in bandages, was sitting in the shadow of a huge square stone. Arlen watched. He could not hear Renzu's words and he moved forward to obtain a better view, when his hand sank into a sticky mass of slime. "Ugh!" he grunted in disgust, lifting his hand. It was covered with a thick, viscous jelly. It was sticky and as he turned his flashlight on the stuff he saw that it was colorless and translucent. It was not a plant or an animal. It did not move, it was cold, and had no structure, nor roots. Shielding his light so that it could not be seen from the campfire, Arlen examined the ground around him. There were other small pools of the stuff in the hollows of rocks and in thick masses on the ground. The captain examined the material more closely. It looked strangely familiar, and some of the text-book science he had learned in college came back to him. He remembered examining stuff like this once under a microscope. It was not petroleum, but something vastly different--something that was synonymous with life. It was protoplasm! <tb> Vic Arlen gasped. "Protoplasm! Inanimate protoplasm!" He forgot he had been nauseated by the slime a moment before and began to examine the stuff closely. Of course, it was protoplasm, it couldn't be anything else. Vic Arlen had studied it. He knew. Nothing could hold water granules in suspension in exactly the same way; nothing had the same baffling construction. But there was a question: scientists admitted life could not exist without protoplasm, but could protoplasm exist without life? In living protoplasm, death alters the structure. But other processes than life could, conceivably, preserve the stability of the substance. This would explain the existence of inanimate protoplasm on Venus.