Hey Mary–I know that this is primarily a blog about whatever happens to be going on in your life, and not about teaching writing, but could you possibly tell a little bit about what you mean by “emotional throughline”? I googled the phrase, both as three words and as two, and found lots of sites where people talk knowingly about emotional throughlines, but not a real good definition or a how-to.
“Throughline” is really an acting term that was coined by Constantin Stanislavski. The idea is that actors should know what their objective is in any scene as well as the line of thought which led from one objective to the next.
In acting you’ll sometimes hear people say that acting is reacting, meaning that no one ever does anything without a reason, this includes emotions. Even chemically induced paranoia comes with a perception of reasons for the paranoia.
If it were possible to chart a character’s emotions through the course of a story the emotional throughline would be the line that connected all the points. Characters go flat when they jump from one emotion to another without any intervening thoughts or reactions.
I’m not saying that you can’t go from happy to angry in a single scene, but something has to happen to cause that shift. That progression is the emotion throughline which propels a character through the story.