At around 20:30 I was leaving the house and looked out towards the SSE direction. Due to our elevation, you can see down the valley towards the Severn Estuary and the Second Severn Crossing. From behind some hills that are a couple of miles away I noticed a bright red light appear which began to rise slowly in the 10 o'clock direction. The light was not flashing as would aircraft lights, and it struck me as looking unusual. It continued to rise and began changing direction, heading towards 12 o'clock. My daughter was waiting for me in the car, and was motioning for me to hurry up. I got in and told her I had been looking at an unusual light. I reversed off the drive and was going to pull away but could see the light through the front windscreen so pointed it out to my daughter. As we watched, the red light slowly moved through the 3 o'clock direction up through 12 o'clock and then back through 9 o'clock, ie. making a large reverse S. Suddenly, what appeared to be a white object dropped from the bottom of the red light (this object was luminous but fainter than the red light, and left a faint trail behind it). The red light immediately started to follow it, slowly at first, then shooting straight down and both objects disappeared. I had to ask my daughter if she had just witnessed the same thing I had, and she confirmed that she had, we were both awe struck. This did not seem to be an aircraft, the lights were unlike navigation lights, and although we often have police helicopters flying around the area on searches, this did not fit with anything I have seen before. I am open to the possibility that it was a drone, although given it's size and the distance I think this unlikely. We also have BAE Glascoed nearby, so I can't rule out a defence project of some kind. I have been watching the sky for many years in the hope of sighting something that I really could not explain by any more likely means, and this is the one. If anyone could tell me what is was, or add any further information, I would appreciate it.