This Inner-Flight spaceship was the last passenger vessel to leave Mars for Terra. All other ships had long since left, returning to safety before the outbreak of hostilities. The passengers were the very last to go, the final group of Terrans to leave the grim red planet, business men, expatriates, tourists, any and all Terrans who had not already gone home. "What do you suppose they want?" the young man said to the girl. "It's hard to figure Martians out, isn't it? First they give the ship clearance, let us take off, and now they radio us to set down again. By the way, my name's Thacher, Bob Thacher. Since we're going to be here awhile--" [Illustration] * * * * * The port lock opened. Talking ceased abruptly, as everyone turned. A black-clad Martian official, a Province Leiter, stood framed against the bleak sunlight, staring around the ship. Behind him a handful of Martian soldiers stood waiting, their guns ready. "This will not take long," the Leiter said, stepping into the ship, the soldiers following him. "You will be allowed to continue your trip shortly." An audible sigh of relief went through the passengers. "Look at him," the girl whispered to Thacher. "How I hate those black uniforms!" "He's just a Provincial Leiter," Thacher said. "Don't worry." The Leiter stood for a moment, his hands on his hips, looking around at them without expression. "I have ordered your ship grounded so that an inspection can be made of all persons aboard," he said. "You Terrans are the last to leave our planet. Most of you are ordinary and harmless-- I am not interested in you. I am interested in finding three saboteurs, three Terrans, two men and a woman, who have committed an incredible act of destruction and violence. They are said to have fled to this ship." Murmurs of surprise and indignation broke out on all sides. The Leiter motioned the soldiers to follow him up the aisle. "Two hours ago a Martian city was destroyed. Nothing remains, only a depression in the sand where the city was. The city and all its people have completely vanished. An entire city destroyed in a second! Mars will never rest until the saboteurs are captured. And we know they are aboard this ship." "It's impossible," the heavy-set business man said. "There aren't any saboteurs here." "We'll begin with you," the Leiter said to him, stepping up beside the man's seat. One of the soldiers passed the Leiter a square metal box. "This will soon tell us if you're speaking the truth. Stand up. Get on your feet." The man rose slowly, flushing. "See here--" "Are you involved in the destruction of the city? Answer!" The man swallowed angrily. "I know nothing about any destruction of any city. And furthermore--" "He is telling the truth," the metal box said tonelessly. "Next person." The Leiter moved down the aisle. A thin, bald-headed man stood up nervously. "No, sir," he said. "I don't know a thing about it."