On a warm Martian evening beside the Great Canal, Joe Caradac, his wife Sarah, and their friends are enjoying a peaceful outing when a broadcast shatters the calm: four escaped Aarnian criminals have fled Mars Detain. Feared throughout the city, the Aarnians can abandon their own bodies, seize others, and hide in plain sight, turning every neighbor into a possible impostor and every glance into suspicion. By morning, the warning has grown more urgent, and Joe's orderly life on Ofei feels suddenly fragile. As he moves through his routine, the story also reveals the hard-won intelligence behind his success: a childhood inability to learn through standard projector-based instruction forced him to master knowledge the hard way and build his career through discipline and ingenuity. That same practicality is tested when Sarah awakens disoriented, speaks in a strange new manner, and rejects him with chilling hostility. Hurt and alarmed, Joe realizes the danger may already be inside his home, and the nightmare on Mars is only beginning. This edition has been fully restored with modern typesetting, custom cover design.