Jazzgirl, I agree that the preamble is a bit of a guddle. The key thing that it makes obscure rather than clear is that one of the thematic items is made up of two unclued lights.
Oh my goodness - a "guddle". That was a favourite word of my (Scottish) late wife. This is the first time I've come across anyone else using it. Thank you, Jack.
Malone, thank you for providing me with an (entirely undeserved) alibi. Jazzgirl, happy to hear you got there. Wil, I am touched; but as a denizen of 9 down it was just a natural usage.
Jack thanks. You say 'undeserved', but I think your subconscious might have registered the title, done something with it and started filling in the blanks, literally. Subtlety is seldom a feature in Doc's titles!