Postmark Ganymede

Mailman, am I? I'll show them!

He brought the Postal Ship down with all the skill of his years in the Patrol, spiralling in around the big satellite of Jupiter as cautiously and as precisely as if he were zeroing in on a pirate lair in the asteroid belt. In its own way, this was as dangerous, perhaps even more so.

Preston guided the ship into an ever-narrowing orbit, which he stabilized about a hundred miles over the surface of Ganymede. As his ship swung around the moon's poles in its tight orbit, he began to figure some fuel computations.

His scratch-pad began to fill with notations.

Fuel storage—

Escape velocity—

Margin of error—

Safety factor—

Finally he looked up. He had computed exactly how much spare fuel he had, how much he could afford to waste. It was a small figure—too small, perhaps.

He turned to the radio. "Ganymede?"

"Where are you, Postal Ship?"

"I'm in a tight orbit about a hundred miles up," Preston said. "Give me the figures on the circumference of your Dome, Ganymede?"

"Seven miles," the colonist said. "What are you planning to do?"

Preston didn't answer. He broke contact and scribbled some more figures. Seven miles of iceworms, eh? That was too much to handle. He had planned on dropping flaming fuel on them and burning them out, but he couldn't do it that way.

He'd have to try a different tactic.

Down below, he could see the blue-white ammonia ice that was the frozen atmosphere of Ganymede. Shimmering gently amid the whiteness was the transparent yellow of the Dome beneath whose curved walls lived the Ganymede Colony. Even forewarned, Preston shuddered. Surrounding the Dome was a living, writhing belt of giant worms.

"Lovely," he said. "Just lovely."

Getting up, he clambered over the mail sacks and headed toward the rear of the ship, hunting for the auxiliary fuel-tanks.

Working rapidly, he lugged one out and strapped it into an empty gun turret, making sure he could get it loose again when he'd need it.

He wiped away sweat and checked the angle at which the fuel-tank would face the ground when he came down for a landing. Satisfied, he knocked a hole in the side of the fuel-tank.

"Okay, Ganymede," he radioed. "I'm coming down."

He blasted loose from the tight orbit and rocked the ship down on manual. The forbidding surface of Ganymede grew closer and closer. Now he could see the iceworms plainly.

Hideous, thick creatures, lying coiled in masses around the Dome. Preston checked his spacesuit, making sure it was sealed. The instruments told him he was a bare ten miles above Ganymede now. One more swing around the poles would do it.

He peered out as the Dome came below and once again snapped on the radio.

"I'm going to come down and burn a path through those worms of yours. Watch me carefully, and jump to it when you see me land. I want that airlock open, or else."

"But—"

"No buts!"

He was right overhead now. Just one ordinary-type gun would solve the whole problem, he thought. But Postal Ships didn't get guns. They weren't supposed to need them.

He centered the ship as well as he could on the Dome below and threw it into automatic pilot. Jumping from the control panel, he ran back toward the gun turret and slammed shut the plexilite screen. Its outer wall opened and the fuel-tank went tumbling outward and down. He returned to his control-panel seat and looked at the viewscreen. He smiled.

The fuel-tank was lying near the Dome—right in the middle of the nest of iceworms. The fuel was leaking from the puncture.

The iceworms writhed in from all sides.

"Now!" Preston said grimly.

The ship roared down, jets blasting. The fire licked out, heated the ground, melted snow—ignited the fuel-tank! A gigantic flame blazed up, reflected harshly off the snows of Ganymede.

And the mindless iceworms came, marching toward the fire, being consumed, as still others devoured the bodies of the dead and dying.

Preston looked away and concentrated on the business of finding a place to land the ship.

The holocaust still raged as he leaped down from the catwalk of the ship, clutching one of the heavy mail sacks, and struggled through the melting snows to the airlock.

He grinned. The airlock was open.

Arms grabbed him, pulled him through. Someone opened his helmet.

"Great job, Postman!"

"There are two more mail sacks," Preston said. "Get men out after them."

The man in charge gestured to two young colonists, who donned spacesuits and dashed through the airlock. Preston watched as they raced to the ship, climbed in, and returned a few moments later with the mail sacks.

"You've got it all," Preston said. "I'm checking out. I'll get word to the Patrol to get here and clean up that mess for you."

"How can we thank you?" the official-looking man asked.

"No need to," Preston said casually. "I had to get that mail down here some way, didn't I?"