Far off in the steaming Venusian jungle, a band of the Chameleon men halted, lifting their mottled faces in the direction of the sound. Closer in, a four-man jungle patrol of Earthmen broke as one man into a run along the trail, their swift-moving bodies swishing the clouds into ragged streamers. At the edge of the viscous river circling the island an armed guard slipped on his infra-red glasses and began searching his area carefully, his special light traveling slowly along the river and its ne