key plot questions

a. why did bai amma switch twins?
b. what was the story/significance of the lost son?
c. what is the narrator's own storyline, if any? are we using her just as a proxy for the oral story-telling aspect? lack of development in narrator's character will leave audience unsatisfied, and secondary storyline must be developed.
d. what is the historical timeline for all the key events?
e. KEY: how will narrator find out the switch of the twins?
f. how does the twin switch impact narrator at a personal level 4 generations later? unless asad (rani's son or raza's son, comes looking for her and there's a love story/digging there? is that too similar to salt and saffron?