Mostly clear blue sky other than a few straight lines at lower altitudes.

Plane directly above leaving a puffy trail. Pretty high up, I couldn't hear it.

I went and got some binoculars to get a better look.

It looked like a "ghost plane", not completely opaque, not really transparent. Kind of a subtle bluish white glow around it.

Watched it through the binocs for about 20 seconds, then the trail cut off abruptly and the plane faded out like a light bulb going dim in a dark room. I had my eyes on it the whole time, right until it faded out.

It was completely blue where it stopped, no clouds obscuring my view. I scanned all around the area, with and without binocs, there was nothing to be seen other than the trail that had just stopped.

I'm in complete disbelief right now. I've seen weird stuff in the sky before, but nothing so clear and obvious that really makes me question whether I actually just witnessed it or not.