Red Planet by Robert A. Heinlein

school.’
    'Neither am I. What's more important, we've got to get word to our folks about the deal that's being cooked up against them.’
    'Say, look—maybe we can phone now!’
    'Do you think he —’ Frank nodded toward the agent. ‘— would let us?’
    'Maybe. Maybe not. We've still got our guns—and I can be pushed just so far.’ Jim got up and went to the agent. ‘Any objection to us using the phone?’
    The agent did not even glance up. ‘Not a bit. Help yourself.’
    Jim went into the booth. There was no local exchange; the instrument was simply a radio link to the relay station on the outer moon. A transparency announced that Deimos was above the horizon; seeing this, Jim punched the call button and asked for linkage to South Colony.
    There was an unusually long delay, then a sweetly impersonal voice announced, ‘Due to circumstances beyond our control calls are not being accepted from Cynia station to South Colony.’
    Jim started to ask if Deimos were visible at South Colony, since he knew that line-of-sight was essential to radio transmission on Mars—indeed, it was the only sort of radio transmission he was familiar with—but the relay station had switched off and made no answer when he again punched the call button. He left the booth and told Frank about it.
    'Sounds like Howe has fixed us,’ Frank commented. ‘I don't believe there is a breakdown. Unless —’
    'Unless what?’
    'Unless there is more to it than that. Beecher may be rigging things to interfere with messages getting through until he's put over his scheme.’
    'Frank, we've got to get word to our folks. See here, I bet we could hole up with the Martians over at Cynia. After all, they offered us water and —’
    'Suppose we could. Where does that get us?’
    'Let me finish. We can mail a letter from here, giving our folks all the details and telling them where we are hiding. Then we could wait for them to come and get us.’
    Frank shook his head. ‘If we mail a letter from here, old frozen face over there is bound to know it. Then, when the cops show up and we are gone, he turns it over to them. Instead of our folks getting it, it goes back to Howe and Beecher.’
    'You really think so? Nobody has any right to touch private mail.’
    'Don't be a little innocent. Howe didn't have any right to order us to give up our guns—but he did. No, Jim, we've got to carry this message ourselves.’
    On the wall opposite them was a map of the area served by Cynia station. Frank had been studying it idly while they talked. Suddenly he said, ‘Jim, what's that new station south of Cynia?’
    'Huh? Where do you mean?’
    'There.’ Frank pointed. Inked on the original map was a station on west Strymon, south of them.
    'That?’ said Jim. ‘That must be one of the shelters for the Project.’ The grand plan for restoring oxygen to Mars called for setting up, the following spring, a string of processing plants in the desert between Cynia and Charax. Some of the shelters had already been completed in anticipation of the success of atmosphere plant number one in Libya.
    'It can't be much over a hundred miles away.’
    'A hundred and ten, maybe,’ Jim commented, looking at the scale.
    Frank got a far-away look in his eyes. ‘I think I can skate that far before dark. Are you game?’
    'What? Are you crazy? We'd still be better than seven hundred miles from home.’
    'We can skate better than two hundred miles a day,’ answered Frank. ‘Aren't there more shelters?’
    'The map doesn't show any.’ Jim thought. ‘I know they've finished more than one; I've heard Dad talking about it.’
    'If we had to, we could skate all night and sleep in the day time. That way we wouldn't freeze.’
    'Hmm ... I think you're kidding yourself. I saw a man once who was caught out at night. He was stiff as a board. All right, when do we start?’
    'Right now.’
    They picked up their bags and headed for the door. The agent looked up, and said, ‘Going