I had this image in my mind of some students jumping off the roof of the boathouse into the lake, like lemmings. Fleshing out the story, I ended up creating a rather ho-hum protagonist. In none of my other stories is there a wishy-washy female, but she seemed to fit in this one.
I gave up trying to get back to sleep and got up around 7AM. Sensibly I opened up my computer and began to tap-tap away, fleshing out an outline. I’ll find it again sometime and finish the job properly. It's a good story.