The Enemy Unknown * Having colonized the worlds of the spiral arm, mankind's three branches-the Terran Hansa, starship-dwelling Roamers, and telepathic Green Priests-are certain the galaxy is theirs for the taking. But when scientists successfully test a device that transforms gas giant planets into new suns, humanity soon discovers the brutal, horrifying price of arrogance in deep space. For Jovian planets are the homeworlds of an undreamt-of alien species, the hydrogues. Infinitely advanced, supremely powerful, and now the victims of accidental genocide, the hydrogues don't seek apologies or reparations. Instead, incredible armadas of invincible, city-sized warships suddenly emerge from the galaxy's billions of gaseous worlds with a single mission-to annihilate every last human being in the universe...