It's much easier to say what it could mean than to find something that actually fits all the criteria.
So far I have considered and discarded Ents, Pippin, and Gollum. Pippin could kinda fit with a stretch - first=Theoden, second=Bergil, third?... but
friends? and Bergil and Theoden didn't really know each other - so no, it couldn't.
And the skies... most of the time it's something like "the skies darkened with nightfall as the travellers walked on"...
This is pretty much not a guess but a post to show that I'm still here...