Saw the promo and I realized how Abhay saves Haseena!!... He does an almost sting operation (w/o cameras involved)
In the promo ' Dipaanita gives the lady the briefcase (dressed in white) and says (or asks for) CD!
So What I am presuming is Abhay along with the Inspector must have played a trick on Dipaanita 'Asking the lady to call for money saying that she (the lady) has a CD that can prove Dipaanita killed Mr. Tyagi. Dipaanita like a fool must have fallen prey to the drama and must have reached there with money (hence the briefcase) and then Dipaanita must have thought "khel hi khatam kar deti hoon" and she must have attacked the lady only to be saved by Abhay! Why else will the police arrive suddenly and arrest her!?
What do you guys think!?
LOVE :)
P.S : Just now I did see a CD in the lady's hand!