"No," answered Clee, still not himself. He added categorically: "I can see Jim. I can see the door. I can see my hands, but I can't see you." "Oh, then it must be true! Xantra _told_ me he was going to make you one of his common slaves; but I hoped--I hoped--" * * * * * This didn't mean much to Clee; but with the words came memory of all that had happened, and with sudden concern he crept over to where Jim was lying, to see how he was. He found him blinking and stirring, aroused by the voices. Quickly he explained the invisible presence to him, warning him to be on guard. "Oh, but I'm a friend--Vivian Gray--kidnapped from Earth just like you!" came quick explanation out of the air. "Xantra stole me from Cape Cod, where I was vacationing, about the time he took you. Xantra is the one whose space ship we are on. He looks much like a man; he is some kind of a man; but he's not from Earth--" "You've _seen_ him?" interrupted Clee, beginning to believe the Voice a little. "Yes," came the instant response; "not when he abducted me--he had made himself invisible for that--but always after. Haven't you yet?" And then, without waiting for his answer, she gave it herself. "But of course you couldn't see him if he's already given you the universal atomic rhythm the slaves have. You'd then be able to see only each other, and the other slaves; not Xantra and not me. "I think he makes his slaves that way for protection," she explained. "They can't very well plot or rebel against him when they can't even see him, and never know but what he's around." "Who are these slaves you keep mentioning?" Jim broke in. "How many of them are there on this ship: and how many like Xantra?" * * * * * "Xantra is the only one of his kind," came the answer. "The slaves are a race of inferior people found on his planet--wherever that is: I couldn't understand, from his explanation, just where. They are creatures much like ugly human beings with a touch of the ape, and are entirely bald, very strong and not very intelligent. There're seven or eight on board. Normally they are good-natured: but sometimes when they have a hard master, like Xantra, they take to hating him; and when they do that they can be very fierce and treacherous. That's the main reason for Xantra's stopping at Earth: to see what kind of slaves we humans will make. He is hoping that we will be more intelligent than those he has--and more docile, and safer to have around." "Well," snorted Jim belligerently, "if Mr. Xantra thinks that I'm going to be safe to have around, he's a lot dumber than _I_ am!" "Oh, it's good to hear you talk that way," the girl's voice went on. "We three have got to stick together, and find some way to escape!