Boone grabbed Staang by the arm and shook him firmly. "But where does Earth come in?" he demanded. Staang gazed at the stern old General and then once again burst into peals of laughter. "You see," he giggled. "We Martians have another name for your Earth. We call it Agar. Your world is the one my ancestors invaded thousands of years ago. Your people are my people's slaves until today." "Wh ... what is he saying?" Nance stammered. "You're crazy," Boone bellowed. "Now I know that you are crazy." "That was the nice thing about our invasion." Staang explained patiently. "The Earthmen did not even realize that they were being invaded--do not even realize today that they are slaves. My people, in their long stay on Earth, have grown even lazier, and particularly their brains have become sluggish during the long years of inaction. Also there have been slight handicaps incurred because of conditions on your world. "For thousands of years there was regular communication between this planet and our invaders on Earth. The records were kept faithfully by the few Martians remaining here, and in my long years of almost complete solitude I learned your language and the history of my people on your world. I knew that perhaps in my lifetime Earthmen would reach this planet. One of my people predicted in 1396 that your world would attain space travel in the latter part of the 20th century." Nance stumbled for words. What creatures of Earth could this being be speaking of, that had such power and progress. But Staang was talking again in his gruff tones. "Correspondence ceased before my birth. I suppose my people grew too lazy, but the main objective had been reached. There is no work for the higher class Martians on your world, only an easy life with servants plenteous." "Wait," spoke up Braun. "You said higher class Martian. Are there different breeds?" "Oh, there are many breeds of Martians. Naturally, we had a slave type here in the height of our civilization, and these slaves were worked into your scheme of things to continue being slaves. They aid you Earthmen so that you may better serve the aristocrat Martians." "But why haven't we seen the Martians?" Braun exclaimed. "I've seen nothing on Earth like you." "No?" said Staang. "Our records say you Earthmen love us and are happy to serve." * * * * * Nance had been studying Staang's features with a practiced eye, the incredibility of his thoughts silencing his tongue. But suddenly he realized that the creature was telling the truth--to a point. He knew that the Martians had invaded Earth. "Look at him, Commander," Nance said. "Don't you see the resemblance. Martians are on Earth, but we call them--" "Good Grief!" exclaimed Commander Boone. Staang snickered. "You call us 'Man's Best Friend,' I believe," he offered. Braun gasped, "_Dogs_."