Manhattan Tower is about a couple by the names of Mary Harper (Mary Brian) and Jimmy Duncan (James Hall). Both work at the Empire State Building: he as an engineer, she's a secretary. They would like to marry and buy a house that they saw advertised in a window in the building lobby, but they need more money. Mary asks her womanizing boss for advice, and he persuades her to give him all her savings to invest. Unbeknownst to her, the boss has speculated in the commodity market, and lost not only his money and that of his wealthy wife, but also some of the firm's funds too. His wife would like to quietly divorce him to marry her politician friend, but the husband asks her for money to avoid a scandal. When Mary changes her mind and asks for the restitution of her savings, her boss refuses and mistreats her. That causes a confrontation between Jimmy and Mary's boss, and they fight. Meanwhile, also the politician and an honest accountant of the firm, who discovered his superior's misdeeds but kept silent fearing to lose his job, decide to confront Mary's boss. During the fight, he takes a gun from a drawer, and menaces them all. He trips and falls through a window to his death. The witnesses decide to declare it was a suicide and go on with their lives.
There are other intertwining stories of people who work at the Empire State Building, and a bank run started by a casual comment by the politician's secretary.