Before Ross could read the message, the name signed to it caught his eye. Horta! The Lord of the Caverns was coming out of his silence! And with what a greeting! "Know, O Queen," read Horta's message, "that I have destroyed three of the Earth-ships, as I shall destroy all who fly against the destiny of the Moon Kingdom. Know, too, that I have destroyed a second Earth city, the place called Los Angeles, as a warning to the Earth people that their destiny is not ours." Ross read it with a sinking heart. Los Angeles! A city of two million people, destroyed! Then it was Horta who had wiped out Nagasaki! Moore pounced on that thought. "Nagasaki, then Los Angeles!" he muttered. Ross turned to Artana. "Any other news?" Artana shook his head. "No. But I have a plan. You know that when the rains come we store them in the great reservoirs, so that our under-world may not be flooded. Then why not loose the waters in the reservoirs, and flood the caverns?" Ross stared in admiration. But he slowly shook his head. "You'd have to kill half your people, Artana, just to dispose of Horta." "But," argued Artana desperately, "Horta will destroy half our people himself, to seize the Kingdom. And he will destroy the Earth folk, too!" Moore spoke up. "The reservoirs are full?" "No," admitted Artana. "The rains have not been heavy. The reservoirs are but half full." He sighed. "Horta might escape the flood." "That's no good, then," Ross said emphatically. "Tell you what, Moore and I will go and scout the Cavern on foot. We may be able to get near enough to the ray works to smash 'em." "You would die," Artana said somberly. "Horta guards his Cavern well." Ross nodded. "Maybe. But there's no other chance. Horta can knock us down out of the air, and he's knocking Earth cities to dust. He must be stopped. If we die, you can hold out on the Peaks, and flood him out when the rains come." "That's right, Artana," Moore agreed. "But let me go, Chief. I'll take a couple of good men. You stay here." "No dice, Harry," Ross assured him firmly. "I'm the head man and it's my job. I'd like to have you along, though." "Sure," said Moore mildly. Artana regarded them with admiration. "You are brave men! But what can I do?" "Just sit tight, Artana, and wait for the rain to fall," grinned Moore. "And when it comes, avenge us." "That will I!" swore Artana. * * * * * They set out in the dark, Moore and Ross and the guide whom Artana had indicated with a gesture. They had covered only half a mile when Ross turned sharply, suspiciously, to the guide. "Sure you speak the Earth tongue?" he demanded. "If you do, why can't you say something?" The guide threw back the cowl-like head covering and Ross caught his breath. "Illeria! What are you doing on this tour?" "I go to die with you, my lord," said the princess simply. "My lord!" squawked Moore. "Excuse me!" He walked forward hurriedly.