Trama

A young couple has a chance to move into a gorgeous duplex in the perfect New York neighborhood. All they have to do is bump off the current tenant, a cute little old lady.

Alex Rose and Nancy Kendricks are a young couple who believe they have found their perfect home to start a family in. There is just one problem. An elderly tenant is staying upstairs and won't move out. Alex and Nancy desperately try everything to convince her to leave, but she refuses to move. Soon, their dream home becomes their home of nightmares.—FilmFanUK

Married New Yorkers Alex Rose and Nancy Kendricks are on the market for their first house, largely for Alex, who, writing his second novel with an imminent deadline for his editor Jean, would like to be able to work from home opposed to using a local Starbucks as his office. Despite being at the upper end of their price range, they believe an agent named Kenneth has shown them the perfect property in Brooklyn, the twist with it being that it is a two level duplex. The plus is that they get two units for the price of one. The minus is that the upper level unit is a rent controlled apartment with an existing tenant, an elderly Irish woman named Mrs. Connelly who they cannot evict. In meeting Mrs. Connelly, they believe she will be a harmless enough tenant, enough for them to purchase the property without even having viewed her unit. They ultimately find that Mrs. Connelly's sweet outer nature masks the tenant from hell, she who seems to be able to manipulate the situation to her benefit as the helpless little old lady. Her constant late night noise leads to Alex needing to nap frequently during the day instead of write, and even when he is lucid enough in the day to write, her constant requests impede his time. Even after Alex foists the responsibility of building manager to Nancy to handle from her office, she a magazine designer, the problem is just spread between the two of them and not just Alex. And any measure they take to curb whatever problem Mrs. Connelly presents in their life, a local beat cop, Officer Dan, always seems to come to Mrs. Connelly's aide against them. As such, they feel the need to take increasingly extreme measures to deal with the problem that is Mrs. Connelly.—Huggo

Alex Rose and Nancy Kendricks are a young, professional, New York couple in search of their dream home. When they finally find the perfect Brooklyn brownstone they are giddy with anticipation. The duplex is a dream come true, complete with multiple fireplaces, except for one thing: Mrs. Connelly, the cranky old lady who lives on the rent-controlled top floor. Assuming she is elderly and ill, they take the apartment but their hopes are quickly dashed when they realize that Mrs. Connelly is an energetic senior who enjoys watching her television at top volume day in and day out and rehearsing in a brass band. A writer, Alex is attempting to finish his novel against a looming deadline. However, each day as he begins to write, he is interrupted by Mrs. Connelly's numerous demands and requests and what begins as a nuisance quickly escalates into an all-out war. When Nancy loses her job and the pair are trapped at home together with Mrs. Connelly, their rage turns to homicidal fantasy as they plot ways to get rid of their no-good neighbor...—Gavin Nelson

Young, professional New York couple Alex Rose (Ben Stiller) and Nancy Kendricks (Drew Barrymore), are in search of their dream home. The seemingly perfect Brooklyn brownstone duplex has one flaw: Mrs. Connelly (Eileen Essell), an old Irish lady who lives on the rent-controlled top floor. Assuming she won't live long, they buy the apartment. Nancy works in advertising and has to go to work all day, working for Herman (Wallace Shawn). While Alex stays at home, writing his novels.

However, they soon realize Mrs. Connelly is lively, enjoys blasting her TV 24-7 and rehearsing in a brass band. A novelist, Alex must finish his latest against a looming deadline. However, he is interrupted constantly daily by Mrs. Connelly (Take out the garbage, sort out the noise in the bathroom pipes) (She calls the plumber for the bathroom pipes which costs $471 for 3 hours of work, while rent is $88 per month) (despite Alex asking her not to disturb during his working hours, she takes him to the pharmacy and to help with her groceries), and it quickly escalates into an all-out war. Her constant interruptions lead to Nancy making a mistake with one of the print copies at work. Nancy is fired from work. Alex starts going to Starbucks during the day as the deadline for the book is within a week. Meanwhile Nancy stays at home to look for a new job.

They try to get her to move out, but she refuses. Next, they try to file a noise complaint against her, but discover that she has gone to the police first and filed a harassment charge against them (they had given her CPR and mouth to mouth when she was choking on a chocolate). Their friends turn against them when she play-acts as the "poor, innocent, old lady" making it appear they are out to harm her.

The duo are stuck as their real estate agent tells them that they way overpaid for the property and they can't get out until they are willing to drop the price drastically. Alex misses his deadline thanks to the old lady's antics (he somehow managed to finish it sitting at Starbucks and the pubs, but then the laptop fell into the fireplace, when Mrs Connelly asked Alex to come and get rid of the rat in her apartment), so they are trapped at home together with Mrs. Connelly with no place to go. Their rage turns to homicidal fantasy as they plot ways to get rid of their manipulative, no-good neighbor.

A water leak from the bathroom pipes get big enough to cover their entire ceiling and starts dripping all over their house. The ceiling rots enough that Mrs Connelly falls through it. The police blame Alex and Nancy for plumbing without license and fine them. They also make them buy a new TV for Mrs Connelly.

Finally, Alex buys a gun to kill Mrs Connelly, but the plan goes awry when Nancy accidentally shoots Alex with the gun. Next Alex and Nancy use the dumb waiter to break into her apartment. But she was anticipating their attack and sends them back the same way they came. They hire a hit-man, Chick (James Remar), to kill her. His asking price for the hit is $25,000. Desperate and needing the money in two days, they sell almost everything they own to pay for the Christmas Eve hit.

Chick breaks into Mrs. Connelly's apartment as planned but fails to kill her as she defends herself with a spear-gun, shooting him in the shoulder. She is incapacitated in the fight, and the duplex catches fire. Nancy and Alex appear to leave her to die, but then return and save her and her parrot. The fire department puts out the fire. Accepting defeat, Alex and Nancy leave, and find out the old woman has just died. Moving away, they contemplate their strange encounter.

We then learn they are not the first to be elaborately scammed by: the Realtor of the duplex, Kenneth (Harvey Fierstein) (Mrs. Connelly's son); the ill-tempered NYPD Officer Dan (Robert Wisdom) (Kenneth's gay lover) who had frequently harassed and distrusted the couple, always siding with Mrs. Connelly in her disputes against them, and Mrs. Connelly herself (who is not in fact dead).

The real-estate scam has been run by the trio for several years: Kenneth sells the ground-floor apartment to an unsuspecting, naive young couple. Then Mrs. Connelly, aided by Dan, harasses them, eventually forcing them to move out. Finally, she fakes her own death so they will never suspect a thing, thus leaving them to collect and live off of the sales commission from the next unsuspecting occupants. Alex and Nancy were their latest victims among many. Despite everything, as they celebrate their latest victory, she admits she actually liked Alex and Nancy and hopes they find success and happiness elsewhere.

A final voice-over by Alex relates that he and Nancy relocated to The Bronx. Like the other couples the trio scammed, they never saw Mrs. Connelly or returned to Brooklyn again. Alex used their unpleasant experience as inspiration for his next book entitled Duplex, which became a best-seller, rescuing him and Nancy from poverty and giving the film a semi-happy ending.