Adultery is not about sex or romance. Ultimately, it is about how little we mean to one another.
The prose as such has to be singing the song the story is telling.
Some animals are secretive; some are shy. A cat is private.
There is always something for which there is no accounting. Take, for example, the whole world.
Of mystery there is no end. Of clarity, there is precious little.
I can only gesture at what makes a story good.