They say that a woman in an abusive relationship never really gets out of it, as lovely, successful Maya (Bipasha Basu) discovers after heaving a sigh of relief too soon.
What they don't say, but should, is that Bollywood concentrates way too much on the "story" part of "horror story". In the case of Aatma, the establishment of a story is what turns it into a could-have-been.
It starts off swell. The scares don't play peek-a-boo. People die in violent and mysterious ways. Mirrors are established as the scene of action.