The cockatoo repeated my last statement again, then rose on its short legs, flapped its wings once and soared off into the sky. Xartal, the Martian illustrator, already had a notebook in his hands and was sketching a likeness of the creature. Ten minutes later we were on the move again. We saw more silver cockatoos and more flagpole trees. Above us, the great disc of Jupiter began to descend toward the horizon. And then all at once Grannie stopped again, this time at the top of a high ridge. She shielded her eyes and stared off into the plain we had just crossed. "Billy-boy," she said to me in a strange voice, "look down there and tell me what you see." I followed the direction of her hand and a shock went through me from head to foot. Down there, slowly toiling across the sand, advanced a party of four persons. In the lead was a little old lady in a black dress. Behind her strode a grizzled Earth man in a flop-brimmed hat, another Earth man, and a Martian. _Detail for detail they were a duplicate of ourselves!_ "A mirage!" said Ezra Karn. But it wasn't a mirage. As the party came closer, we could see that their lips were moving, and their voices became audible. I listened in awe. The duplicate of myself was talking to the duplicate of Grannie Annie, and she was replying in the most natural way. Steadily the four travelers approached. Then, when a dozen yards away, they suddenly faded like a negative exposed to light and disappeared. "What do you make of it?" I said in a hushed voice. Grannie shook her head. "Might be a form of mass hypnosis superinduced by some chemical radiations," she replied. "Whatever it is, we'd better watch our step. There's no telling what might lie ahead." We walked after that with taut nerves and watchful eyes, but we saw no repetition of the "mirage." The wind continued to blow ceaselessly, and the sand seemed to grow more and more powdery. For some time I had fixed my gaze on a dot in the sky which I supposed to be a high-flying cockatoo. As that dot continued to move across the heavens in a single direction, I called Grannie's attention to it. "It's a kite," she nodded. "There should be a car attached to it somewhere." She offered no further explanation, but a quarter of an hour later as we topped another rise a curious elliptical car with a long slanting windscreen came into view. Attached to its hood was a taut wire which slanted up into the sky to connect with the kite. A man was driving and when he saw us, he waved. Five minutes later Grannie was shaking his hand vigorously and mumbling introductions. "This is Jimmy Baker," she said. "He manages _Larynx Incorporated_, and he's the real reason we're here." I decided I liked Baker the moment I saw him. In his middle thirties, he was tall and lean, with pleasant blue eyes which even his sand goggles could not conceal. "I can't tell you how glad I am you're here, Grannie," he said. "If anybody can help me, you can."