"I wonder...." Tau gazed beyond the Khatkan to the barren ground where leopard and rock ape had ceased to be. "This magic is a tricky thing, sir. It builds and feeds upon a man's own imagination and inner fears. Lumbrilo, having triggered ours, need not strive at all, but let us ourselves raise that which will attack us." "Drugs?" demanded Jellico. Tau gave a start sufficient to take him out of Dane's loose hold. His hand went to the packet of aid supplies which was his own care, his eyes round with wonder and then shrewdly alert. "Captain, we disinfected those thorn punctures of yours. Thorson, your foot salve.... But, no, I didn't use anything--" "You forget, Craig, we all had scratches after that fight with the apes." Tau sat down on the ground. With feverish haste he unsealed his medical supplies, laid out some containers. Then delicately he opened each, examined its contents closely by eye, by smell, and two by taste. When he was done he shook his head. "If these have been in any way meddled with, I would need laboratory analysis to detect it. And I don't believe that Lumbrilo could hide traces of his work so cleverly. Or has he been off-planet? Had much to do with off-worlders?" he asked the Chief Ranger. "By the nature of his position he is forbidden to space voyage, to have any close relationship with any off-worlder. I do not think, medic, he would choose your healing substances for his mischief. There would only be chance to aid him then in producing the effects he wants. Though there is often call for first aid in travel, he could not be _certain_ you would use any of your drugs on this trip to the preserve." "And Lumbrilo _was_ certain. He threatened something such as this," Jellico reminded them. "So it would be something which we would all use, which we had to depend upon...." "The water!" Dane had been holding his own canteen ready to drink. But as that possible explanation dawned in his mind, he smelled instead of tasted the liquid sloshing inside. There was no odor he could detect. But he remembered Tau commenting on the powdered purifier pills at their first camp. "That's it!" Tau dug further into his kit, brought out the vial of white powder with its grainy lumps. Pouring a little into the palm of his hand he smelled it, touched it with the tip of his tongue. "Purifier and something else," he reported. "It could be one of half a dozen drugs, or some native stuff from here which we've never classified." "True. There are drugs we have found here." Asaki scowled down at the green mat of jungle. "So our water is poisoned?" "Do you always purify it?" Tau asked the Chief Ranger. "Surely during the centuries since your ancestors landed on Khatka you must have adapted to native water. You couldn't have lived otherwise. We must use the purifier, but must you?"