A few days before her wedding, secretary Marjorie Lee Nancy Kwan decides she wants to experience more of life before settling into married life. On her last day working at a large cosmetics firm, which happens to be the day of the office Christmas party, she arrives in a provocatively frilly dress and steps into a moment she hopes will feel different from the routine. Her appearance catches the attention of several male colleagues, including her lecherous boss Godfrey Deane Terry-Thomas and a visiting sales manager named Craig Jimmy Logan, who invites her to lunch. Deane's secretary Monica Joyce Blair becomes noticeably upset by his interest, signaling the awkward tension behind the glittering party mood.
After having the company's new Vampire Look makeup tested on her by a colleague named Quentin Victor Spinetti, Marjorie allows Craig to buy her a new dress and joins him for lunch at his hotel suite. The encounter quickly shifts the mood from flirtation to pressure as he makes advances, and she panics, fleeing the suite in a rush. She returns to the office with a jittery sense of resolve, choosing to temper the day with a touch of mischief rather than submission. Back at the workplace, she uses her Christmas bonus to purchase liquor, aiming to make the party more exciting than the modest gathering Deane had planned, a move that signals her willingness to experiment with freedom while still keeping a handle on the consequences. When her fiancé Andy Donald Churchill arrives to pick her up, Marjorie reveals her plan to savor the time she has left as a single woman and sends him away, setting the stage for a night that will push those boundaries further.
As the evening unfolds, the party grows increasingly wild and sexually charged, moving beyond propriety and into a more chaotic revelry. Marjorie, repulsed by the excess around her, takes action to reset the scene by triggering the ceiling’s fire sprinkler system, drenching everyone and washing away the earlier intoxicated bravado. The mood then shifts abruptly from anger to unexpected celebration when a phone call arrives with news that Ralph Mansford David Sumner has just become a father, a development that softens the atmosphere and reconstitutes the group’s energy. The party, though uproarious, begins to dissolve, and Marjorie finds Andy waiting for her, leading to a quiet reconciliation as the night ends—an ending that acknowledges the tension between longing and commitment while offering a tempered closure to an evening that tested everyone involved.
