Really Fast light heading due South

I was in my son's room and heard a commotion outside. I looked out and saw that there were some kids messing around and they had taken the balloons that are sometimes outside of the office, across the parking lot. They ran west in front of the office and around the corner and then south away from me. As they did this they let go of the balloons which floated up into the sky. I was watching the balloons float higher and higher and lost sight of them, and since I was already looking at the sky, I decided to see what stars I could see.
At this time is when I saw what I first thought was a satellite. I quickly realized that this was about twice the size of what a satellite usually looks like, although it was the same brightness as the typical satellite, maybe a tad brighter.  The other thing that I noticed was that it was the fastest satellite that I have ever seen. I have seen hundreds of satellites in my years of stargazing, but nothing this fast. It wasn't anywhere near as fast as a shooting star, but for anything else, it was fast. I would estimate that it was going 2-3 times as fast as a quick moving satellite.
I looked away from it for just long enough to raise the blinds the rest of the way up, they were half way down, when I looked back where it should be, it was either gone or turned off.  Almost forgot to mention, it was heading due south.  I also checked on Heavens Above and didn't see satellites for the time I saw it or any going from North to South. It also was not the ISS. I've seen it many many times and know that that was not it.  The ISS is much brighter than what I saw and also much slower than what I saw, not to mention that it had already passed by this area at at 9:07pm, and went from WNW to ENE, so it was well to the north of me.