The ribbon was a magnificent idea—the more magnificent because of its simplicity. It would reflect back otherwise wasted sun-heat to a too-cold planet and make it warmer. There was probably only an infinitesimal actual mass of powder in the ring, at that. Tens or scores of tons in all. Hardly more.
The planet for which it had been established was the third world out. As is usual with sol-class systems, the third planet's distance from the sun was about a hundred twenty million miles. It had icecaps covering more than two-thirds of its surface. The sprawling white fingers of glaciation marked mountain chains and highlands nearly to the equator. But there was some blue sea, and there was green vegetation in a narrow belt of tropicality.
Calhoun jockeyed the Med Ship to position for a landing call. This was not Merida II, but there should be a colony here. That glowing ribbon had not been hung out for nothing.
"Med Ship Esclipus Twenty," he said confidently into the spacephone mike. "Calling ground. Requesting co-ordinates for landing. My mass is fifty tons. Repeat, five-oh tons. Purpose of landing, to find out where I am and how to get where I belong."
There was a clicking. Calhoun repeated the call. He heard murmurings which were not directed into the transmitter on the planet. He heard an agitated, "How long since a ship landed?" Another voice was saying fiercely, "Even if he doesn't come from Two City or Three City, who knows what sickness—" There was sudden silence, as if a hand had been clapped over the microphone below. Then a long pause. Calhoun made the standard call for the third time.
"Med Ship Esclipus Twenty," said the spacephone speaker grudgingly, "You will be allowed to land. Take position—" Calhoun blinked at the instructions he received. The co-ordinates were not the normal galactic ones. They gave the local time at the spaceport, and the planetary latitude. He was to place himself overhead. He could do it, of course, but the instructions were unthinkable. Galactic co-ordinates had been used ever since Calhoun knew anything about such matters. But he acknowledged the instructions. Then the voice from the speaker said truculently: "Don't hurry! We might change our minds! And we have to figure settings for an only fifty-ton ship, anyhow."
Calhoun's mouth dropped open. A Med Ship was welcome everywhere, these days. The Interstellar Medical Service was one of those overworked, understaffed, kicked-around organizations which is everywhere taken for granted. Like breathable air, nobody thought to be grateful for it—but nobody was suspicious of it, either.
The suspicion and the weird co-ordinates and the ribbon in space combined to give Calhoun a highly improbable suspicion. He looked forward with great interest to this landing. He had not been ordered to land here, but he suspected that a Med Ship landing was a long, long time overdue.
"I forgot to take star-pictures," he told Murgatroyd, "but a ribbon like this would have been talked about if it had been reported before. I doubt star-pictures would do us any good. The odds are our only chance to find out where we are is to ask." Then he shrugged his shoulders. "Anyhow this won't be routine!"
"Chee!" agreed Murgatroyd, profoundly.