"_Calling ground_," said the recorded voice yet again. "_Med Ship_ Esclipus Twenty--" It went on through the formal notice of arrival. Murgatroyd waited in pleasurable anticipation. When the Med Ship arrived at a port of call humans gave him sweets and cakes, and they thought it charming that he drank coffee just like a human, only with more gusto. Aground, Murgatroyd moved zestfully in society while Calhoun worked. Calhoun's work was conferences with planetary health officials, politely receiving such information as they thought important, and tactfully telling them about the most recent developments in medical science as known to the Interstellar Medical Service. "Somebody," said Calhoun darkly, "is going to catch the devil for this!" The communicator loudspeaker spoke abruptly. "Calling Med Ship," said a voice. "Calling Med Ship _Esclipus Twenty_! Liner _Candida_ calling. Have you had an answer from ground?" Calhoun blinked. Then he said curtly: "Not yet. I've been calling all of half an hour, and never a word out of them!" "We've been in orbit twelve hours," said the voice from emptiness. "Calling all the while. No answer. We don't like it." Calhoun flipped a switch that threw a vision screen into circuit with the ship's electron telescope. A starfield appeared and shifted wildly. Then a bright dot centered itself. He raised the magnification. The bright dot swelled and became a chubby commercial ship, with the false ports that passengers like to believe they looked through when in space. Two relatively large cargo ports on each side showed that it carried heavy freight in addition to passengers. It was one of those workhorse intra-cluster ships that distributed the freight and passengers the long-haul liners dumped off only at established transshipping ports. Murgatroyd padded across the Med Ship's cabin and examined the image with a fine air of wisdom. It did not mean anything to him, but _tormals_ imitate human actions as parrots and parrakeets imitate human speech. He said, "_Chee!_" as if making an observation of profound significance, then went back to the cushion and again curled up. "We don't see anything wrong aground," the liner's voice complained, "but they don't answer calls! We don't get any scatter-signals either. We went down to two diameters and couldn't pick up a thing. And we have a passenger to land. He insists on it!" * * * * * By ordinary, communications between different places on a planet's surface use frequencies the ion-layers of the atmosphere either reflect or refract down past the horizon. But there is usually some small leakage to space, and line-of-sight frequencies are generally abundant. It is one of the annoyances of a ship coming in to port that space near most planets is usually full of local signals. "I'll check," said Calhoun curtly. "Stand by."