The Ice Folk:
had built a great civilization;
but do not feel loss because it is in ruins;
have found a way to live without buildings or engines;
have been free to think for many ages;
do not fear extinction;
know that everything ends although nothing really ends;
want their lesser brethren to have time to evolve;
are possibly a single organism with the forests and the lakes;
are aware when friends come to Ghost Lake;
possibly respond to the Shaman's chanting;
somehow destroyed approaching hostile aircraft at a distance;
will become clients of the Empire although to them it means nothing;
can reach Terra but only through - dreams?
My point as ever is that Anderson incorporates so much background information so effortlessly into the story that we might be surprised at how much there is when it is summarized separately.