This is pure speculation so take this with a pinch of salt but i have pieced together a story : Talwars and Ruddanis are involved in some shady underhand stuff.......Aarushi got wind of this fact and started gossiping about this in school...Talwar asks her to put a tight lid on her mouth but she does not listen......Banita Ruddani gives an ultimatum to Rajesh that if he does not reign in his daughter, she will come to serious harm....a veiled threat is given...Rajesh gets scared and fearing for safety of his beloved daughter, starts locking her inside her room at night.....cos Banita Ruddani visits them very often and could harm her....
Ruddanis then hatch a plan with their servant Rajkumar.... Rajkumar pursuades Krishna and reminds him of all the humiliation that he has undergone at the hands of Talwar....
Ruddanis, on that fateful night, invite Talwars over late at night, for a meeting.... At the same time, Rajkumar and Krishna enter Talwar residence....Hemraj greets them....they have a drink and after drinks, Hemraj is taken to terrace where he is killed to cover up for Aarushi's impending murder...then Krishna and Rajkumar enter aarushi's room and murder her...
Both exit by the terrace route...... Talwars return and don't check on the servant or their daughter assuming they are sound asleep.....
Next morning, the maid comes and the whole drama unfolds....
