Young and happily wedded couple, novelist Alex Rose and lifestyle magazine writer Nancy Kendricks, are looking for the right place at the right price to live in New York City so they can build a home and start a family. Their search comes to an end when the realtor Kenneth shows them a unit in a beautifully appointed turn-of-the-century Brooklyn brownstone which, much to their surprise, is actually a sumptuous duplex. However, a minus: a current tenant in the form of Mrs. Connelly, an elderly tenant who resides in a sublet portion of the second floor of the duplex apartment afforded under the protections of rent control. Kenneth brings them upstairs to show them the second floor and introduce them to Mrs. Connelly, but when she answers the door, she is quite sickly and declines to invite them in. They are at first reluctant to purchase the unit, but ultimately agree on the basis of, among other things, the assumption that Mrs. Connelly should not be terribly long for this world and when she passes on they will regain control of the upper floor of the duplex and their apartment will not only double in space, but in value as well.