I got some good work done today. I have a gap, however, because I still haven't zeroed in on my MacGuffin.
Hitchcock once said that a MacGuffin is "the thing the spies are after but the audience don't care." Some people call it a plot coupon. It might be the solution to the mystery, or a magic sword, or nuclear secrets. When Hitch was making the movie Notorious, the MacGuffin was uranium - and at the time of production, the whole concept of making a nuclear bomb was a major government secret. Hitch claimed that the FBI investigated him, but he just had to explain that he wasn't making a movie about nuclear secrets. It was a love story. (Actually it was an excuse to make a movie with a kiss that flouted all the production codes.) The MacGuffin could as easily be industrial diamonds as anything else.
However, that all became a moot point after Hiroshima, because none of it was a secret anymore, so the movie continued with uranium as the MacGuffin.
Because MacGuffins are replaceable, it is possible to write a lot of a story without deciding what it will be. However, I like a MacGuffin to really fit the story. It's like a title - sure you could have a different one, but I want the RIGHT one. It affects why the spies want it, and "why" is all about motive, and motive is all about character and drama.
So ... I'm still working on my MacGuffins in this story. I do know that the ultimate MacGuffin (on the surface) will be a gold pearl which is rumored to have mystical powers. However, I think for most of the book it will act as a red herring. That is, it's something everybody ultimately wants, but there are more immediate goals that are hidden by it. And I think that at first Pauline doesn't want it at all. I think she wants something much more personal, like to thwart blackmail or some other plot - and the evidence is hidden with or near the pearl. (And even when it becomes the main MacGuffin, it may actually still be a red herring that leads to a greater one. That's the thing with episodic stories. Each episode needs its own MacGuffin.)
Tomorrow I'm getting ready to go on a trip, but I expect to still be able to post next week. I will probably have to switch from writing to reading for a while, though.