itoo agree that dubey jee is the kidnapper for sure.
he is the only person who will benefit by yash and arti's divorce, and not only that he will also benefit by remarrying yash co this way he blocks arti's ways of going back to yash.
also this scheme will give immense pain to yash as he has to not only give up his love, but also marry someone else and ultimately live without his son also just like dubey has lost prashant forever.
this plan ina way also removes all signs of doubts from his head and instead blames others like papa schindiya and bua.
or also he could have tied hands with papa schindiya initially during custody case when sp was himself against arti and yash.
now he could be blackmailing him as you must have noticed tears in sp's eyes when yash announced he will remarry.
dubey is the mastermind but who are his helpers or is he blackmailing?????