They'd have torn him apart. Those vulpine faces, with the distended nostrils and the bared teeth!

And now he was being chased by one man. But that man was Lew's brother.

Here was the rim, and Alf was still well behind. Carter slowed as

he went over, knowing that the way down would be rougher. He was just going over the edge when a rock ten yards away exploded ill white fire.

Alf had a flare pistol.

Carter just stopped himself from scrambling out of the buggy to hide in the rocks. The buggy lurched downward and, like it or not, Carter had to forget his terror to keep the vehicle upright.

The rubble around the crater's rim slowed him still further. Carter angled the buggy for the nearest rise of sloping sand. As he reached it, Alf came over the rim, a quarter-mile behind. His silhouette hesitated there against the bloody sky, and another flare exploded, blinding bright and terrifyingly close.

Then Carter was on the straightaway, rolling down sloping sand to a perfectly flat horizon.

The radio said, "Gonna be a long one, Jack."

Carter pushed to transmit. "Right. How many flares do you have left?"

"Don't worry about it."

"I won't. Not the way you're throwing them away."

Alf didn't answer. Carter left the radio band open, knowing that ultimately Alf must talk to the man he needed to kill.

The crater which was home dropped behind and was gone. Endless flat desert rose before the buggies, flowed under the oversized wheels and dropped behind. Gentle crescent dunes patterned the sand, but they were no barrier to a buggy. Once there was a Martian well. It stood all alone on the sand, a weathered cylindrical wall seven feet high and ten in circumference, made of cut diamond blocks. The wells, and the slanting script written deep into their "dedication blocks," were responsible for the town's presence on Mars. Since the only Martian ever found-a mummy centuries dead, at least-had exploded at the first contact with water, it was generally assumed that the wells were crematoriums. But it wasn't certain. Nothing was certain about Mars.

The radio maintained an eerie silence. Hours rolled past; the sun slid toward the deep red horizon, and still Alf did not speak. It was as if Alf had said everything there was to say to Jack Carter. And that was wrong! Alf should have needed to justify himself!

It was Carter who sighed and gave up. "You can't catch me, Alf"

"No but I can stay behind you as long as I need to."

"You can stay behind me just twenty-four hours. You've got , forty-eight

hours of air. I don't believe you'll kill yourself just to' kill me."

14 Don't count on it. But I won't need to. Noon tomorrow, you'll be chasing me. You need to breathe, just like I do."

"Watch this," said Carter. The 0-tank resting against his knee was empty. He tipped it over the side and watched, it roll away.

"I had said. He smiled in relief at his release

from that an extra tank, he damning weight. "I can live four hours longer than

you

can. Want to turn back, Alf?"

"No."

"He's not worth it, Alf. He was nothing but a queer."

"Does that mean he's got to die?"

"It does if the son of a bitch propositions me. Maybe you're a little that way yourself?"

"No. And Lew wasn't queer till he came here. They should have sent half men, half women."

"Amen."

You know, lots of people get a little sick to their stomachs about homosexuals. I do myself, and it hurt to see it happening to Lew. But there's only one type who goes looking for 'em so he can beat up

on em.

Carter frowned.

Latents. Guys who think they might turn queer themselves if you gave 'em the opportunity. They can't stand queers around because

queers are temptation."

"You're just returning the compliment."

"Maybe."

Anyway, the town has enough problems without-things like

that going on. This whole project could have been wrecked by someone like your brother."

"How bad do we need killers?"

"Pretty badly, this time." Suddenly Carter knew that he was now his own defense attorney. If he could convince Alf that he shouldn't be executed,

he could convince the rest of them. If he couldn't-

then he must destroy the bubble, or die. He went on talking as persuasively as he knew how.

"You see, Alf, the town has two purposes. One is to find out if we can live in an environment as hostile as this one. The other is to contact the Martians. Now there are just fifteen of us in town-"

"Twelve. Thirteen when I get back."

"Fourteen if we both do. Okay. Each of us is more or less necessary to the functioning of the town. But I'm needed in both fields. I'm the ecologist, Alf I not only have to keep the town from dying from some sort of imbalance, I also have to figure out how the Martians live, what they live on, how Martian life forms depend on each other. You see?"

"Sure. How 'bout Lew? Was he necessary?"

"We can get along without him. He was the radio man. At least a couple of us have training enough to take over communications."

"You make me so happy. Doesn't the same go for you?"

Carter thought hard and fast. Yes, Gondot in particular could keep the town's life-support system going with little help. But- "Not with the Martian ecology. There isn't-"

"There isn't any Martian ecology. Jack, has anyone ever found any life on Mars besides that man-shaped mummy? You can't be an ecologist without something to make deductions from. You've got nothing to investigate. So what good are you?"

Carter kept talking. He was still arguing as the sun dropped into the sea of sand and darkness closed down with a snap. But he knew now it was no use. Alf's mind was closed.

By sunset the bubble was taut, and the tortured scream of incoming breathing-air had dropped to a tired sigh. Lieutenant-Major Shute unfastened the clamps at his shoulders and lifted his helmet, ready to jam it down fast if the air was too thin. It wasn't. He set the helmet down and signaled thumbs-up to the men watching him.

Ritual. Those dozen men had known the air would be safe. But rituals had grown fast where men worked in space, and the most rigid was that the man in charge fastened his helmet last and unfastened it first. Now suits were being removed. Men moved about

their duties. Some moved toward the kitchen to clean up the vacuum-induced havoc so Hurley could get dinner.

Shute stopped Lee Cousins as he went by. "Lee, could I see you a minute?"

"Sure, Mayor." Shute was "the Mayor" to all bubbletown.

"I want your help as a writer," said Shute. "I'm going to send in a quite controversial report when we get within range of Earth, and I'd like you to help me make it convincing."

"Fine. Let's see it."

The ten streetlamps came on, dispelling the darkness which had fallen so suddenly. Shute led the way to his prefab bungalow, unlocked the safe, and handed Cousins the manuscript. Cousins hefted it. "Big," he said. "Might pay to cut it."

"By all means, if you can find anything unnecessary."

"I'll bet I can," Cousins grinned. He dropped on the bed and began to read.

Ten minutes later he asked, "Just what is the incidence of homosexuality in the Navy?"

"I haven't the faintest idea."

"Then it's not powerful evidence. You might quote a limerick to show that the problem's proverbial. I know a few."

"Good."

A little later Cousins said, "A lot of schools in England are coeducational. More every year."

"I know. But the present problem is among men who graduated from boys' schools when they were much younger."