When a young mother encounters a random woman in a crowd, she is mysteriously filled with an unceasing desire to kill her, and must do so before the other woman kills her first.

I suggest? it might help if the logline were to play the concept of a? hate mate against that?of a soul mate to cue readers, help them grasp your story conceit.? For example, something like:

After a?woman?loses her soul mate to?cancer, she discovers her hate mate, a woman whom she?has the overwhelming?desire to kill as strong as her desire was to love.

(Or her hate mate could be a man. Whatever.)

As I posted earlier, I think?the hook of the story is the hate mate concept.??From her overwhelming desire arises her objective goal: to kill her.??The dramatic question is:? will she follow through, will she succeed in killing the hated other? (That the goal is negative?does not disqualify it?from being a valid objective goal.)?

I think you can squeeze a lot of suspense out of the concept.? Best wishes.

I love the concept of a kill mate as the antithesis of the soul mate.? So very Jungian.? That, for me, is the story hook.? Not what she does, but the?WHY,?the?psychological motivation driving the plot, her actions.

But it's?a tough concept to explain?and ?sell in a few words.? Keep working in it, Tom.? I think?the concept, if not the logline (yet), is a?winner.

'gentle librarian' and 'sunny waitress' change the tone, they sound like descriptors for a comedy. I don't actually want to see a gentle librarian want to kill someone, that sounds like an opposite for the sake of an opposite. I like there to be some level of competency in characters.