The butler did it
After being otherwise occupied for several hours and eating tea, it was good to get back to work on the whodunnit. In the last few hours I’ve not written any code, nor drawn any art, but I have produced a prodigal amount of waste paper. The end result is that the algorithms which drive the scenarios (it’s dynamically generated each time) seem to be working - at least on paper.
The camera’s gone walkabouts, so pictures of the mess will be up later. Tomorrow is implementing everything, but for now I’m off to bed.