Congratulations to both @Doctor J and @NickD  on their joint win in a tightly fought end to the April Challenge.   After a small discussion the photo has been offered by NickD and agreed by all parties    The preamble ...    " I was messing with vapour and light for a photography project last year, and this reminded me of the smoky, fleapit cinemas of my childhood, but I reckon it's pretty wide open to interpretation."           Simple rule