Okay, I can see subtle and sophisticated here.
At the end of my WIP (the first in a series), the way she maneuvers to solve the OS changes their relationship RS which enables the MC to accomplish the story goal.
Details of my story require too much background. Imagine this: an undercover Jewish doctor involved in resistance activities is avoiding to be caught and sent to the death camps OS, but he has special skills MC that make him desirable as a personal physician RS to an SS general (Obergruppenführer) OC who turns a blind eye to his possibly being Jewish if only to always have his expertise on hand to secretly help with his rare medical condition.
So, the doctor's relationship with the Obergruppenführer reaches some point, from stranger to personal physician RS--but that also enables the doctor to be safe (and protected) from the death camps OS, for now.
That's kind of how I've spun my story. Is it too causal? Or is it subtle and sophisticated?