"I managed to smuggle this. It's the only way we'll make it out of here! Don't worry about the alarms, just stay close to me. I have a plan." Once in the exit lock, Curt had a moment of foreboding as he watched the huge inner doors close behind them. Again he applied the electronic key. The outer doors opened. They stepped into the unending lava waste of Mercury's nightside. No sound reached them now. But Curt knew that already, in the Prison Dome behind them, the alarm was being given. He hugged the outer _crystyte_ wall, hurrying along it away from the exit. The others sped after him. Rikert clicked on his speaker. "Emmons, what the hell! This is crazy!" "Is it?" Curt didn't stop his half running pace. "You two agreed I was to handle this! They won't think to look for us so close!" They stopped at last, huddling against the wall. A half mile behind them the lock was opening again. Two of the surface-cars, on caterpillar treads, blasted out and away. Searchlights slashed the ragged terrain. "They won't spend too much time," Curt said. "They figure we're dead men already." Never yet had a prisoner succeeded in reaching the Mercurian cities, hundreds of miles away on the twilight-strip. Curt's face went grim as he thought of _their_ chances. They weren't trying to reach a city! Their destination was the little mountain-range somewhere on the nightside. Ten minutes later the surface-cars came back. The Prison lock opened and closed. Grimly, the three fugitives headed into the wastes. There'd be no pursuit now. * * * * * Rikert strode forward purposeful as an automaton, and he was much like an automaton in other ways. As silent and grim. As big and hard, and as cold. The square lines of his face were unmoving beneath the crystyte helmet. Kueelo was smaller, but he managed to keep pace. His eyes burned brightly in his finely chiselled face. Only the high-pitched, mad little tune on his lips seemed to keep him going. Curt Emmons, perhaps more than the others, knew the chances against them. His gray eyes flicked worriedly to the dial inside his helmet. It registered slightly over half, which meant they had two more hours of oxygen. It would be close! He set his lips tight, glanced at his companions. He knew Rikert would bear up. It was Kueelo who worried Curt. The little Martian was leg weary, keeping pace on sheer grit alone--grit that stemmed somehow from that eerie little tune eternally on his lips! "We're a little ahead of schedule," Curt lied. "Let's take five." Kueelo sank down gratefully on the hard rock. Even Rikert eased his bulk down. Then in annoyance he thrust a hand against the Martian. "Damn it, Kueelo, turn it off!" Abruptly the tune died on Kueelo's lips. He stretched out, gazed with infinite longing at the black sky and myriads of mocking stars. He searched for Mars.