So that was the reason Kortha had been given! Ilse held her eyes shut tightly. Her left hand bit its long fingernails into the naked skin of her flank. Pain! Pain would help to cancel the sodden ache in her heart. "Yes," she whispered. "I know. But Mars doesn't know that, and Mars has to be told. If Mars could hear the truth from your lips-- "Come with me to radio-city Ruuzol, Kortha. Broadcast to Mars. Be the first to let the planet know you and Guantra are friends. You be the first; you, his friend." Kortha nodded slowly. He felt Ilse's hands squeezing his. "It must be a secret, though. We can't let Guantra know, or the surprise would be spoiled. You have to come with me." She saw his eyes light after a moment, and she knew she had won; that he would go with her away from the Blue Grotto and its magical machine that could steal men's minds from them and give them something different in exchange. She turned, dove for the water. Kortha was beside her, sinking into the blue fire of water, dropping down and down past coral growths and bannery weeds that slithered in ripples as the currents wafted them to and fro. Following her threshing legs, clinging to coral branches as did she, pulling himself along, Kortha went under a ledge and rose swiftly in a tiny cave. Ilse said as she treaded water, "My 'copter is outside. It will take us to Ruuzol." Ruuzol was the communication center of all Mars. A vast glassite paraboloid was built on a flat mesa against a cliffside. It housed vast turbines and generators, and the central controls, as well as laboratories and rows of dwellings, where the men lived. A fountain-dotted park gave the small city an air of leisure. Their 'copter swooped in over the flat plains surrounding the mesa, casting its shadow from the high cliffs all around the plain out across the flatlands, up onto the mesa sides. Flanking the great transparent paraboloid were the twin tubes, taller than the dome itself, thrusting their glass-and-steel structures two thousand feet into the air. At their tops, three metal planes were inserted into their trunks; planes that were the secret of the Martian radio beams, planes that sent the spacevox rocketing to Earth and Venus, and the direct broadcasts out over the sandy wastes of Mars. Ilse flashed her 'copter past a tube and spiralled gracefully to one of the white landing strips beyond the dome. They walked toward the paraboloid. Ilse showed credentials to the guards at the entrance; then they were through and into the cool, pleasant air of the paraboloid, moving on one of the glass walks. The harsh tones of the communicator sprang to speech around them: "The princess Ilse. The princess Ilse. The Emperor desires speech. The Emperor desires speech." Kortha muttered something under his breath, but Ilse pretended not to hear him, saying, "It will only be a moment."