Faint light zips back and fourth across sky

While standing outside with my dog, I noticed a light in the sky which looked to be moving quite quickly due to it's apparent FAR distance. The light was very faint and at first glance seemed to be a satellite, just a pin-prick gliding in a southerly direction away from me... as I watched it, it's brightness seemed to fade and then suddenly started jerking around in the sky- It seemed to be VERY far away, as I said earlier,(Like a sattelite in orbit) and was making 90 degree turns and sudden stops... it was very impressive as well as the 10 minute duration of the display. This continued untill a SECOND light came across the sky towards it, though this time it was most definetly an airplane of some sort with trademark blinking lights and flying in an even and steady path... as the blinking light of the air-plane approached the jerky "UFO" light, it instantly darted downward and over the horizon, while the air-plane continued on a straight easterly path. I observed this looking south/south-east from the north of Tallahassee, Florida.