bits of it almost make sense, but it's not a coherent whole

Bingo.

I love the Paternosters, and I keep looking sideways at those (including a certain colleague of mine) who are all, "Good grief, why do we keep going back to Victorian London?" Well...if you have a set of recurring characters who don't actually move in time, seems to me you're going to end up doing back to where they are a bunch. This is not rocket science...

what was all that stuff he was writing on the floor with the stick of chalk?

Good question!! I just know I wish he'd kept going with that!