Thousands of years ago mankind conquered the stars... and of course it brought all of its wars along with it. One small, though highly advanced, faction was losing ground fast. Then, suddenly, it disappeared. It turns out that they decided to hide in the planetary nebula of NGC 6543, better known as the Cat's Eye Nebula. Now they are forced to emerge, and strive to secure a place for themselves in the universe. For this to work, the colony must be: MASSIVE. It holds a population of at least 1,000,000 and growing. Probably more. Probably much more. Self-Sustaining. It will have been running for thousands of years. Hidden. It has not been noticed during this time. NGC 6543's CSPNe may actually be a binary star. In this book it is. I would like the colony to be as close to the CSPNe(s) as possible, if not actually within one. I would like the science to be fairly hard. Exceptions: limited access to exotic (negative mass-energy) matter (they use Alcuiberre drives). possible access to scrith-like materials if necessary. So... would this setting be at all feasible? What would be necessary to pull this off? Thank's in advance for your input.