So that music the drones are making inside the walls is a clock counting down to zero hour. They now know they've got only two years and a handful of months left; if this is happening worldwide without exception, then no more humans will remain on Earth when the Raps are done. The question of survivors living outside the colonies is even more important now. Assuming the aliens don't stay and make our planet their new home, hidden settlements may be humanity's only hope for a future. I wonder what the authority bigwigs have been promised. That they alone will be spared to reboot the human race, I'm sure it's something like that. And they can go right on believing it until the camp is empty and they get marched to the showers last.