Steven Dalt should have died in that cave on the planet Kwashi. After all, as the natives say, of a thousand people attacked by the cave-dwelling alaret, nine-hundred-and-ninety-nine will die. Dalt survives, but not without personal cost: he has picked up a passenger: an alien intelligence transferred itself from the alaret to take up residence in his brain. Steven Dalt will never be alone again. But Pard, as Dalt names the alien who shares his life, doesn't believe in freeloading. He pays his rent by using cellular-level consciousness to maintain Dalt's body in perfect health, no disease, no aging. And now Dalt appreciates the full meaning of the Kwashi natives' saying: of a thousand struck down by an alaret, nine-hundred-and-ninety-nine will die. But the thousandth will not die...ever.