Apartment movie is based on the story of a girl who comes from a small town to this big city. Preeti Sengupta (Tanushree Dutta) is an airhostess living in with her boyfriend Karan Malhotra (Rohit Roy). They share a nice 2BHK apartment in the northern suburbs of Mumbai and are befriended by their elderly neighbor Madhusudan Tanha (Anupam Kher), a struggling poet and lyricist. Tanha is a loner living with his only companion, a Persian cat whom he lovingly calls Shehzadi.
Preeti is possessive and has issues with trust. When she mistakenly suspects her boyfriend to be unfaithful, she throws him out of the house but soon realizes she can't afford the payment on the apartment on her own. On the advice of a fellow airhostess, she advertises for a tenant to share her apartment. Enter Neha Bhardwaj (Neetu Chandra), a modest small-town girl asking for accommodation. Very impressed by her simplicity and respectfulness, Preeti believes she has found a perfect roommate. The two girls soon become close - their camaraderie leads them to even become companions.
Until things begin to go disastrously wrong - slowly and steadily. Preeti's seemingly normal life is thrown off gear - with a series of incidents that take her by surprise. Is it just co-incidence or is someone deliberately causing all the trouble? Is Neha really as simple as she seems? In the grip of mystery, unforeseen and gruesome events and murder as its heinous best, the truth seems shocking as it in folds. As Neha and Preeti are torn apart by suspicion, deceit and betrayal, the question is - will the romance between Karan and Preeti survive or...