It's one such idea that's back to whisper at me at the moment.
It's not a plot bunny (i.e. something that's going to distract me from MoulderingBook). It's ... a surfacing. A seedling that's ready to germinate and reach for the light.
In other words, I think it may be the rousing of the project I'll be working on once I'm done with MoulderingBook.
I have a number of semi-ideas for possible projects on a backburner, but this one seems to want to jostle to the front of the queue.
I love the sense of all these ideas simmering away inside me, bubble-popping to the top of the cauldron from time to time, then sinking back into the stew for a while longer. Some end up stuck to the bottom of the pot and never evolve into anything more. Others may require a notebook of their own at some point ...