A bunch of religious zealots were going to load themselves into that massive ship, that small self-sustaining world, and launch themselves into the darkness between the stars. Generations would live and die in it, and if they were mind-bendingly lucky enough to find a planet worth living on the end of the journey, the people who came out of it would never have known Earth or Mars or the Belt. They’d be aliens already. And if whatever had made the protomolecule was out there to greet them, then what?
