Tripping over the perfect metaphor

When I was writing Daughter of Mystery I avoided posting too much work-in-progress in part because there was enough of a mystery plot going on in the story that I worried about spoilers for eventual readers. How's that for optimism? But the current project The Mystic Marriage (aka "book 2") doesn't really have the same puzzle aspects, so I think I'm going to be a bit more comfortable with posting snippets as I work.

At any rate, the starting idea of having alchemy as the underlying spine of the action was, to some extent, arbitrary. One of the main viewpoint characters had been noted previously as being interested in alchemy, and what she needed for this story was some sort of Great Project through which she was going to redeem the family honor by her own efforts. It turned out to be exactly the sort of story-seed that sent out the roots and tendrils that I needed to get the plot rolling. But when I started layering in the critical events and conversations sketching out the main romantic arc, the primary metaphor that popped up involved food. Which was working very nicely for the purpose but didn't really tie in with the main plot's symbolic structure.

This week I got hit with the inspiration for the alchemy tie-in. ( Some Background. )