"The Vestans," Kenniston added dully, "are semi-intelligent _parasites_. The live by attaching themselves to and taking control of some other creature's body. They do it by jabbing in those tiny, needle-like antennae to contact the victim's nervous system. Thereafter, the Vestan controls the victim's body absolutely. When the victim dies or is hurt, the Vestan simply detaches himself and fastens upon a new victim." * * * * * Horror was on the white faces of the others. Murdock gulped and asked, "Then Bray--" "Bray is beyond saving now," Kenniston said. "The Vestan parasite will control his body till he dies. The Vestans always like to attach themselves to human beings--they know that a man's body is more versatile in its capabilities than an animal's." Twilight was beginning to descend upon the little clearing in the jungle, for the sun had gone down during the last few minutes. In the gathering dusk, the jungle loomed dark and brooding about them. Overhead, the sky of this World with a Thousand Moons was burgeoning into its full glory. The hundreds of meteor-moons that spun across the heavens were shining brighter and brighter in the deepening dusk. Captain Walls broke the spell of horror and dread. "We'd better get back inside the ship for tonight," he said nervously. "We can't do anything about repairs until tomorrow, anyway. By then we'll have figured out some way to deal with those devilish creatures." Murdock said bitterly to Kenniston, "Bray's end is your fault, Kenniston. You brought him and us and these women into this place, all for the sake of that brother of yours." "He'll stand trial for that when we get back to Mars," the captain vowed. "Even if he wasn't one of Dark's crew originally, by helping them he's made himself a space-pirate, liable to execution." Kenniston made no attempt to defend himself. He knew they wouldn't understand why he had sacrificed them for Ricky's sake, even if he told them. He and Holk Or were locked in one of the little cabins, after it had been carefully searched. The crewman Thorpe was stationed as a guard outside their bolted door. Holk Or, who had bandaged his burned arm, looked around the dark little cabin disgustedly. "This is a devil of a fix to get into!" swore the Jovian. "Here we've reached Vesta with the stuff, but can't let the chief know." Kenniston asked him earnestly, "Holk, would John Dark really shoot Ricky if I didn't deliver the equipment? He said he would, but you know he needs Ricky." Kenniston was clinging to this last shred of hope for his brother. John Dark and his pirates did need Ricky. For Ricky was a physician--Doctor Richard Kenniston of the Institute of Planetary Medicine.