Writer's Fallout Shelter

Welcome back. I'm glad to see you again.

Your post, especially the comment about keeping every part of the story in mind as you're writing, made me think of E.L. Doctorow's Ragtime. There's a line in the first chapter that is almost a throwaway line. It's easy to miss it, but it comes back to be very, very relevant toward the end of the book, at least for one of the characters the story is following.

It's a different type of layering than what I was originally considering, but Ragtime is one of those books where the storylines don't seem to be connected at all, but they are very skillfully interwoven, flowing in and out of one another, without ever touching, until they build to the end.