Suddenly, it cut off. The Med Ship approached the planet to which it had been ordered by Sector Headquarters now some months ago. Calhoun examined the nearing world via electron telescope. On the hemisphere rolling to a position under the Med Ship he saw a city of some size, and he could trace highways, and there were lesser human settlements here and there. At full magnification he could see where forests had been cut away in wedges and half-squares, with clear spaces between them. This indicated cultivated ground, cleared for human use in the invincibly tidy-minded manner of men. Presently he saw the landing-grid near the biggest city—the half-mile-high, cage-like wall of intricately braced steel girders. It tapped the planet's ionosphere for all the power that this world's inhabitants could use, and applied the same power to lift up and let down the ships of space by which communication with the rest of humanity was maintained. From this distance, though, even with an electron telescope, Calhoun could see no movement of any sort. There was no smoke, because electricity from the grid provided all the planet's power and heat, and there were no chimneys. The city looked like a colored map, with infinite detail but nothing which stirred.
A tiny voice spoke. It was the voice of the space-port.
"Calling Med Ship. Grid locking on. Right?"
"Go ahead," said Calhoun. He turned up the communicator.
The voice from the ground said carefully:
"Better stand by your controls. If anything happens down here you may need to take emergency action."
Calhoun raised his eyebrows. But he said:
"All set."
He felt the cushiony, fumbling motions as force-fields from the landing-grid groped for the Med Ship and centered it in their complex pattern. Then there came the sudden solid feeling when the grid locked on. The Med Ship began to settle, at first slowly but with increasing speed, toward the ground below.
It was all very familiar. The shapes of the continents below him were strange, but such unfamiliarity was commonplace. The voice from the ground said matter-of-factly:
"We think everything's under control, but it's hard to tell with these paras. They got away with some weather-rockets last week and may have managed to mount warheads on them. They might use them on the grid, here, or try for you."
Calhoun said:
"What are paras?"
"You'll be briefed when you land," said the voice. It added, "Everything's all right so far, though."
The Aesclipus Twenty went down and down and down. The grid had locked on at forty thousand miles. It was a long time before the little ship was down to thirty thousand and another long time before it was at twenty. Then more time to reach ten, and then five, and one thousand, and five hundred. When solid ground was only a hundred miles below and the curve of the horizon had to be looked for to be seen, the voice from the ground said:
"The last hundred miles is the tricky part, and the last five will be where it's tight. If anything does happen, it'll be there."
Calhoun watched through the electron telescope. He could see individual buildings now, when he used full magnification. He saw infinitesimal motes which would be ground-cars on the highways. At seventy miles he cut down the magnification to keep his field of vision wide. He cut the magnification again at fifty and at thirty and at ten.
Then he saw the first sign of motion. It was an extending thread of white which could only be smoke. It began well outside the city and leaped up and curved, evidently aiming at the descending Med Ship. Calhoun said curtly:
"There's a rocket coming up. Aiming at me."
The voice from the ground said:
"It's spotted. I'm giving you free motion if you want to use it."
The feel of the ship changed. It no longer descended. The landing-grid operator was holding it aloft, but Calhoun could move it in evasive action if he wished. He approved the liberty given him. He could use his emergency-rockets for evasion. A second thread of smoke came streaking upward.
Then other threads of white began just outside the landing-grid. They rushed after the first. The original rockets seemed to dodge. Others came up. There was an intricate pattern formed by the smoke-trails of rockets rising and other rockets following, and some trails swerving dodging and others closing in. Calhoun carefully reminded himself that it was not likely that there'd be atomic war-heads. The last planetary wars had been fought with fusion weapons, and only the crews of single ships survived. The planetary populations didn't. But atomic energy wasn't much used aground, these days. Power for planetary use could be had more easily from the upper, ionized limits of atmospheres.
A pursuing rocket closed in. There was a huge ball of smoke and a flash of light, but it was not brighter than the sun. It wasn't atomic flame. Calhoun relaxed. He watched as every one of the first-ascended rockets was tracked down and destroyed by another. The last, at that, was three-quarters of the way up.
The Med Ship quivered a little as the force-fields tightened again. It descended swiftly. It came to ground. Figures came to meet Calhoun as, with Murgatroyd, he went out of the airlock. Some were uniformed. All wore the grim expressions and harried looks of men under long-continued stress.
The landing-grid operator shook hands first.
"Nice going! It could be lucky that you arrived. We normals need some luck!"
He introduced a man in civilian clothes as the planetary Minister for Health. A man in uniform was head of the planetary police. Another—
"We worked fast after your call came!" said the grid operators. "Things are lined up for you, but they're bad!"
"I've been wondering," admitted Calhoun dryly, "if all incoming ships are greeted with rockets."
"That's the paras," said the police head, grimly. "They'd rather not have a Med Service man here."
A ground-car sped across the space-port. It came at a headlong pace toward the group just outside the Med Ship. There was the sudden howl of a siren by the space-port gate. A second car leaped as if to intercept the first. Its siren screamed again. Then bright sparks appeared near the first car's windows. Blasters rasped. Incredulously, Calhoun saw the blue-white of blaster-bolts darting toward him. The men about him clawed for weapons. The grid operator said sharply:
"Get in your ship! We'll take care of this! It's paras!"
But Calhoun stood still. It was instinct not to show alarm. Actually, he didn't feel it. This was too preposterous! He tried to grasp the situation and fearfulness does not help at such a time.
A bolt crackled against the Med Ship's hull just behind him. Blasters rasped from beside him. A bolt exploded almost at Calhoun's feet. There were two men in the first-moving ground-car, and now that another car moved to head them off, one fired desperately and the other tried to steer and fire at the same time. The siren-sounding car sent a stream of bolts at them. But both cars jounced and bounced. There could be no marksmanship under such conditions.
But a bolt did hit. The two-man car dipped suddenly to one side. Its fore-part touched ground. It slued around, and its rear part lifted. It flung out its two passengers and with an effect of great deliberation it rolled over end for end and came to a stop upside down. Of its passengers, one lay still. The other struggled to his feet and began to run. Toward Calhoun. He fired desperately, again and again—