One idea leads to another. The acquisition of a 2.5 million watt flashlight (silly cheap at auto stores - looks like a Police radar gun, and has a car headlight in it) and "painting" subjects setting off a mental hunt for unlit places to play. Sitting at a friend's kitchen table this place came to mind, by the time I left his house it had become an obsession.
Figuring the shot out itself, it took some time, there are 4 different light sources, all with different temps, not counting the flashlight in my hand. That sorted, and the right shooting spot selected, and then the wait, and wait, and wait..for the "right" train.