Regulations provide

"I've got four here," said Barnes. His voice was on the verge of cracking, it seemed to Joe. "I'll be seeing you, boys."

"Cut it out," said Joe uneasily. "We'll get out of here and have clam chowder for desert. Though I must admit the 'how' of doing so eludes me at the moment. Four hours — and they've souped this up to about eight cee, I'd judge — we'll be a long way from home."

They moved slowly about the room. There were two other chambers open to them, one on either side, but there was no exit. They decided that one contained the machinery for producing and circulating the foul nitrogen peroxide atmosphere. The other was a storage chamber for the heavy water used in the reactor.

There was a small store of tools, but none that would dent or burn the doors. Barnes and Hamilton had brought along their kits, but they held nothing that would help.

They sat down on rows of cannisters. Joe looked about at the blank-faced, monstrous-looking suits that housed his companions. They were silent, thinking that this was a stupid way of winding up. There was Barnes with only four hours of oxygen to go. They couldn't share theirs with him.

"Why couldn't we wreck the atmosphere plant?" asked Barnes suddenly. "Maybe we could even find a way to discharge it into space. That would fix those clamshells' little red wagon good."

"Yes, but what good would it do us?" said Joe. "We'd still be locked in here and no way out."

"We'd be taking them with us, anyway —" Barnes muttered savagely.

"Cut it out," said Joe. "This is entirely impersonal. Get your gray matter agitating on the physical problem of getting out. You can hate them afterwards. Now, as I see it, the problem is to persuade them to open up the door voluntarily. We can't possibly get out unless they do."

"You put it so neatly," said Hamilton. "What are we going to do? Offer a free ride to the one that opens up first?"

They were young, Joe thought, and they'd never been trained for danger. Life was too soft for kids nowadays. It was probably the first time these two youngsters had ever considered the possibility of fatal circumstances occurring to them.

They wouldn't be of much help.

He turned to Litchfield. "What do you think?"

"I'm thinking, but there's not much production so far. I don't see what we can do to make them turn us loose."

"Irritate 'em."

"Like itching powder under their shells, huh?"

"Maybe there's something here that we could pour into the atmosphere system. Let's have a look anyway. Tear open some of these cans."

He glanced at the clock face in the helmet. A full half hour had passed since the doors had first been clamped. Three and a half to go — for Barnes.

Litchfield held up an open can. He had a steel claw full of mushy substance. "Must be food. Do you know what they eat?"

"No. Keep going and keep thinking."

The two technicians were halfheartedly obeying Joe's instructions, but they had no enthusiasm for the task. They'd given up completely, he thought. He and Litchfield would have to carry them.

He kept on, opening boxes and storage cabinets, trying to identify the substances encountered, his mind constantly examining and rejecting each item for possible means of attracting the captors to the locked chamber.

He wandered on into the chamber where the huge tanks of heavy water were stored.

"We haven't found a supply of drinking water, have we?" said Joe.

"All food as far as I can tell here," said Litchfield.

"On a planet with an atmosphere of nitrogen peroxide I wonder if there wouldn't be an absence of open bodies of water. Perhaps the metabolism of any life there would have to exist without water."

"I don't know," said Litchfield. "Why? Weil — I suppose not. Constant reaction would produce nitric acid rain. In time there would be no more water because the process would go to termination. On a planet like that they'd probably handle water the way we do nitroglycerine. So —" Litchfield suddenly shouted. "Joe! That's it! We'll irritate these crabs until they'll swear they're being broiled alive."

"I don't get it," said Hamilton. "What are you going to do?"

"Pipe some of this water over to the atmosphere pumps. Those crabs will be breathing nitric acid vapor - providing they breathe. If they don't, I'll bet it will sting their hides and send them back here yammering to get in."

"Yeah ... yeah ... it might do it," breathed Barnes. His voice was almost pitiful at this apparent reprieve.

"Well, let's not bank on it until it's done," Joe growled. "This won't be easy with what we've got to work with."

"Turn about will have to be within an hour —" Barnes murmured.

They found a coil of tubing among the supplies. It was soft enough to bend, but it couldn't be melted or soldered with the small torch that their kits contained. They had to improvise a coupling to the tank outlet. The tubing was too soft to permit tight clamp. It's size would only permit a butt joint.