Billions of planets may be ripe for life, even intelligence. So where is Everybody? Do civilizations make the same fatal mistakes, over and over? Might we be the first to cross the mine-field, evading every trap to learn the secret of Existence?Astronaut Gerald Livingstone grabs a crystal lump of floating space debris. Little does he suspect it's an alien artifact, sent across the vast, interstellar gulf, bearing a message."Join us!" – it proclaims. What does the enticing invitation mean? To enroll in a great federation of free races?Only then, what of rumors that this starry messenger may not be the first? Have other crystals fallen from the sky, across 9,000 years? Some have offered welcome. Others… a warning!This masterwork of science fiction combines hard-science speculation and fast-paced action with the deeply thoughtful ideas and haunting imagery that David Brin (best-selling author of Earth and The Postman) is known for in more than twenty languages.