"Payments for the oxygen," said the stocky man.
"What do you mean?"
A weak, sardonic smile edged across their faces. "They weren't told," the tall man said.
Harvey boiled over. He grabbed one man by the throat. "Told what, goddamn you? Talk!"
The pale eyes stared into his. The sardonic smile stayed on the man's lips. "Told that you'll have to work all day, every day, dawn to dark"—his voice hardened viciously—"to pay for the oxygen you breathe." His smile widened as he saw the alarm in Harvey's face. Harvey loosened his grip, but the man kept his face close to his. "You see that tube of oxygen on your back? That will last you one day. When you get a new one, you will owe a hundred credits. Do you understand now? You'll never be able to stop working, because you can't get ahead of that hundred credits a day, you just about make it if you work all day—and you have to make it, do you understand, you fool?—you have to, if you want your oxygen tomorrow, if you want to breathe."
Harvey watched dazedly as the two guides turned and started away down the road, and then, abruptly, the stocky one looked back and yelled back, "You're slaves! All of you! You're the same as us! You're slaves!"
Ruth, wide-eyed, was waiting at the doorway for him, when he came back. "You heard them?" Harvey said shakily.
"I heard," Ruth said in a quiet voice.
"Lord, what did I get you into?"
She put a hand on his arm. "There's nothing to grieve about. If we find that things just don't work out, we'll stick it out for two years and save up enough for our return passage."