"Don't cry for me,
Yes... tears on my keyboard (rather than my pillow). "It's not a good movie unless you have a good cry." (but same person will be bitter if there is not a kissy happily-ever-after ending.) Here is my basic contention - truly great books need to upset you emotionally, or at least stir you emotionally. And sometimes as an author I feel like one of those people who pull heartstrings to make the character - and reader puppets dance. The fault with this metaphor is that I dance with them, only moreso. Yes. I have ended up crying on my keyboard. Signy killing her dog in A MANKIND WITCH, (which I found almost impossible to edit, because I couldn't see the screen), the despair and courage of Vlad's sister down in the dungeons beneath Elizabeth Bartoldy's castle... somewhere in most of the books I have written (OK not Karres so much). I find I am so involved with my characters it hard to be dispassionate (which is possibly why I rationalise that it would be a bad thing.) I rage against the wrongness of it, I am torn by the pain. It is very, very hard when you are being god-in-author form not just to leave out/edit away these tragedies (as you can only do in books) because you'd haave to be... odd not to want to fix them. But I think that... would be a mistake. Because without the tragedy that resolution (which is very different from 'it didn't happen') cannot happen. Mind you, I think there is sometimes a desire in readers (and maybe editors?) to be entertained without that. Sort like a book being a hooker that gives pleasure without any of the other strings. I dunno. I can't write that.
So: if we need to do it... leaves us with how does the writer achieve that heart-string dance? I am really not sure how to do this for other people (I am not even sure if I do, or if I am right that it is a good thing. Angst is plainly considered good, but sentiment? Out of fashion, methinks.)
There are obviously evocative words. Powerful themes, love, loyalty, pain... And then there is taking your reader with you into those...
I've always found this is the antithesis of transitions. You MUST show.
But what works for you? Do you want to be emotionally involved? Do you fall for the hero/heroine? Do you want the disaster/misery/ heart-tear fixed?
How do you make yourself (or your reader) care that much?