Slow Moving Black Triangle Over Fields

We were driving back towards Shrewsbury at approx 0230 hours along Berwick Road just outside Shrewsbury. To the right were large fields which are part of an agricultural show ground. Directly over the fields wa a large solid, black triangle shaped craft moving very slowly over the top of the field. It was about 200ft off the ground and moving in a South Easterly direction. It had a faint white glow at each corner, but the one at the front seems to change colour slightly as it moved. It was easily about the size of a C130 aircraft that the military used.
We decided to pull over near to Coton Manor to try and get an image of this weird thing in the sky. We got one picture and as we got out of the car it turned to face us, and shot a bright white light or beam in our direction. We ducked down next to our vehicle, and when we looked again it had disappeared. We heard a strange humming noise as it fired this beam of light towards us, and a whoosh of air straight after. We think it shot of and speed in a Northerly direction.
We've never seen anything like this before, and are used to seeing mitary aircraft in the area, due to the nearby airbase. But that has helicopters and nothing of large size. This was certainly not anything conventional because of the way it moved.