What happens when humanity finally reaches the stars—only to be told to leave? In Fredric Brown's thought-provoking sci-fi short story "Keep Out", Earth's first interstellar explorers make contact with an advanced alien race. But instead of a warm welcome, they receive a chilling warning: humanity is not ready. With his trademark wit and sharp storytelling, Brown delivers a powerful tale about human nature, technological progress, and the barriers we may never cross. A gripping and clever story, "Keep Out" remains a classic exploration of our place in the universe.