There was a thunderstorm. Usually I don't mind them, though they always scared Ginger. Only,last night at 3:24 AM exactly*, there was a clap of thunder so loud that I felt the floor vibrate,and As I was half asleep, I was so startled that my heart was must have been doing it's equivalent of donuts in the driveway.
That is all.
I know this because I looked at the clock immediately afterward so that I would know for future reference.