Shimmering, preternaturally flying disc seen in front of clouds in Fredericton, N.B..I was a passenger crossing the Princess Margaret Bridge on my way to dinner with my boyfriend and his sister. I looked up into the clouds, and noticed a very still, strange and large preternaturally bright/disc formation. It seemed to shimmer, almost a bit mercurial.It was certainly not a star or airplane of any sort. It hovered/paused long enough in front of the clouds for me to try and get my companions attention to see it, then vanished.Nobody else caught a glimpse.Its movement seemed very deliberate, very efficient, and not of this world. The speed and (oddly enough) expressiveness of its movement hinted at an awareness of being witnessed (by me or who knows else could have seen it in the vicinity) I am an artist, who is not particularly knowledgable on the topic. I don't watch much tv or movies about aliens/spacecraft etc, but I am fascinated and open to the possibility of such things.