Story genesis: I love it when a story suggests itself from everyday life.  I was on the train, when sitting opposite me was a large chap who had a woman's diamond engagement ring on his little finger.  He saw that I had noticed it and appeared uncomfortable.  It wasn't clear whether he was going to a situation where he would need it or coming away from something where it had been thrown away and he was looking after it.  I wonder...

Broad shoulders with muscles visible under the t-shirt, taut against the train’s motion.  A woman’s engagement ring gleamed on his smallest finger.  He twitched it, sweating.