So, Natasha wants a divorce from Karthik. Even though she believes that she still loves him a lot, she was very hurt over the situation when Karthik was recovering from his coma and coming out of the coma, and seemed to respond to touching from Jhanvi rather than Natasha, which hurt her terribly. Since she now realizes that maybe Karthik is actually more interested in Jhanvi than her, and hence she decides to go for a separation and divorce from Karthik although he pleads with her not to do this.
So, Neha and Vikram setup a plan whereby Neha tries a ladies holiday to Singapore (apparently she is fit enough to travel on a plane even though in pregnancy, many doctors do not easily agree to let their patients travel for long distances) while Vikram talks about a necessary meeting in Singapore, and both of them get them on the plane (and switch off their mobile phones so that Ram and Priya cannot call them and complain about what they have done). However, the ice between the two has not yet melted, and then everybody in India gets to know that the plane has crashed. And they show both Ram and Priya in wounded positions in the aftermath of the plane crash, lying on the ground, with plane debris and other people lying around them. Will they be now separated for 20 years ? Given that it is a Balaji serial, this is very much possible.