(Spoilers ahead) Novel concept. Good story. Awesome acting by Mr. Massey. His stares gave me chills.
Bad screenplay. Rani's character at the start of her marriage should have been given more screentime instead of it getting narrated like a story. We never find out how many days have passed after any incident unless the characters narrate it in the background. We don't know how Rani has been coping with her husband's absence. She has been trying to talk to him but that too gets narrated instead of portrayed. All attempts look feeble and half-hearted. She feels guilty after the cheating incident but that guilt is shown in a few seconds and suddenly she is sati savitri.
Taapsee was really disappointing. She did no justice to Rani's impulsive and bubbly character. Rani's attraction for Neel was supposed to be blinding, as if she was head over heels into him. But Taapsee looked bland. Her shock looked staged when Neel betrayed her. Her cries looked all fake even when she was apparently ready to commit suicide (fake tears don't help, they look like makeup instead of emotional outbursts).
There were these little things+Taapsee that prevented me from rooting for anything at all. 2.5 stars.