Overhead, they heard the thrumming of rockets. Barry smiled mirthlessly. "Grey has his scouts out." "They will see nothing in the mist," Deisanocta said confidently. But she turned to the radio and contacted her field captains. "It is the same everywhere," she told him. "The enemy's ships circle helplessly overhead." "I don't like it," Barry said. "If I know Craig Grey, he's up to something. Those ships aren't up there without a reason." Deisanocta ignored this, her eyes speaking plainly her disappointment in the Earthman she'd believed a friend. Instead of answering him, she turned to the Martian who had waited so patiently and silently for her orders. "We will eat," she said haughtily to Barry, after a few swift words to the other. "Perhaps Earth food will revive your courage." "Thank you." Barry ignored the slur, and sat down beside her where the Martian was spreading a cloth on the ground. The thrumming of rockets died away as they began, and the Princess glanced significantly at Barry Williams. He turned to the food in silence, a frown of concentration on his forehead. They had dried horse meat from Earth, the staple dish of the natives, a poor grade of canned corn that was like a thin mush, and hard, wafer-thin pieces of bread. "My courageous followers won these provisions in battle," Deisanocta said softly. Barry was finding even the unappetizing menu inviting. He ate rapidly, being careful not to work too deeply into what he knew was a slender store of food. The girl watched him as she nibbled at her food. The scorn in her face slowly faded into sad reproach. It wasn't until the Princess poured a glass of liquid and set it before Barry, that the far-away look was swept from his eyes by sudden understanding. The liquid was Martian Wrin, a delicious, invigorating drink from native roots, much coveted and seldom obtained by Terrestrials. Even through the white mist that shrouded them, it sparkled from ruby depths. The color galvanized Barry Williams. * * * * * "Red!" he exclaimed. "_Infra-red!_ Grey's ships were sweeping the desert with infra-red rays, and taking photographs with film sensitive only to those rays. When those prints are developed, he'll have the location of every mist-producing unit that's on Mars, and of your followers!" "I don't understand," stammered the bewildered Deisanocta. "I know nothing of these things." "Just believe me," he pleaded. "Order your men and the mist units to move at once!" Deisanocta moved to the radio and obeyed. Barry Williams' heart leaped. She believed in him, her recent doubt forgotten before the vigor of his arguments. "And us?" she asked. "We're all right, being underground. The infra-red rays won't betray us in the photographs. Listen!"