Chuck is young, ambitious, likeable, charming and a bachelor who works for the Consolidated Life Insurance Company whose chief executives use his apartment for extra curricular amatory pursuits. Mr Dobitch - Mortgages and Loans Dept - borrows Chuck's keys, and apartment against the promise of rapid promotion within the company.
But once word gets out that his apartment is ground zero for secretive trysts, one executive after another also borrow said key - and all with the same promise of advancement within the company.
Enter Fran Kubelik, a waitress in the company restaurant and a girl whom Chuck has a crush on but unbeknownst to him has been having an affair with the very much-married personnel director and Chuck’s boss, J.D. Sheldrake.
Things turn vastly more complicated when Fran is dumped by Sheldrake on Christmas Eve and she tries to commit suicide in Chuck's bedroom. Chuck’s neighbor, Dr. Dreyfuss, saves her life but suspects that Chuck was the cause of the suicide attempt. Not wanting to “out” his boss he cops to the allegations.
Once the smoke clears, Sheldrake tries to resume his affair with Fran much to the heartbreak of our amorous hero. Not willing to stand by any longer, Miss Olsen, Sheldrake's former mistress and current secretary, decides to acquaint his wife about the history of his affairs and before long he is moving into the YMCA. This emboldens Sheldrake to freely pursue Fran but when he meets Chuck to sort things out and resume the use of the apartment as his love nest, Chuck bravely decides to give him the keys, not to the apartment but to the executive bathroom at Consolidated Life.
As Chuck is packing to leave New York for quieter pastures, Fran arrives, unannounced, and tells him that she is over and done with Sheldrake. The two stare into each other’s eyes and we are left with hope that Chuck has a greater reason to stay than to leave.