Jack and Kate, who have been a couple since their college days, find themselves at JFK Airport as Jack prepares to embark on a twelve-month internship with Barclays in London. Kate expresses her deep concern that this separation could negatively impact their relationship, urging him to reconsider his decision. Jack, however, reassures her that their love is resilient enough to survive the distance, and he boards the flight.
Fast forward thirteen years, Jack is now a bachelor living a lavish lifestyle as a Wall Street executive in New York City. He has achieved immense financial success and is in the midst of orchestrating a multi-billion dollar merger, even calling for an emergency meeting on Christmas Day. On Christmas Eve, he receives an unexpected message prompting him to contact Kate, but despite their shared history, he chooses to ignore it and does not return her call.
As he heads home that night, Jack encounters a young man named Cash at a convenience store, who claims to possess a winning lottery ticket valued at $238. The store clerk dismisses his claims, asserting the ticket is fake. In a moment of desperation, Cash brandishes a gun to threaten the clerk, prompting Jack to intervene and offer to buy the ticket, which Cash begrudgingly accepts.
After their transaction, Jack tries to engage with Cash, who poses a thought-provoking question about what might be missing in Jack's life. Cash cryptically suggests that Jack is about to experience the consequences of his choices and walks away, leaving Jack puzzled. That night, he goes to sleep, only to awaken the following morning in a suburban New Jersey home alongside Kate and their two children. Confused and disoriented, he makes a frantic attempt to return to his condo and office in New York, but discovers that neither doormen recognize him.
On the street, Jack encounters Cash yet again, who is now immaculately dressed and driving Jack's own Ferrari. Cash teases that there is more to the situation, referring ambiguously to "The Organization" and suggesting that Jack is receiving "a glimpse" of what his life could have been had he chosen to stay with Kate.
As Jack acclimates to this alternate reality, he begins to embrace a life he could have shared with Kate, where he is now a car tire salesman under her father's guidance, and Kate is thriving as a non-profit lawyer. His young daughter, Annie, initially views him as a friendly alien but ultimately helps him navigate this new existence. Jack experiences ups and downs but gradually finds fulfillment as he reconnects with his children and rekindles his romance with Kate.
His chance encounter with his former boss, Peter Lassiter, during a tire-related mishap allows Jack to impress him with his business acumen. This prompts Lassiter to offer Jack a position, complete with a lucrative salary and additional benefits, leading Jack to reconsider the lifestyle he has grown fond of. However, Kate argues that they should cherish their current happiness instead of pursuing a different life.
When Jack next encounters Cash, who is now working as a store clerk, he pleads to remain in his newfound reality. Cash coldly reminds him that "a glimpse," by nature, cannot last forever. That evening, Jack struggles to stay awake but ultimately succumbs to sleep, waking up once more to find himself in his original life.
Determined to reconnect with Kate, who is in the process of moving out of her upscale townhouse before a trip to Paris, Jack decides to forgo finalizing a crucial acquisition deal. Over the years, Kate has also prospered as a corporate lawyer and had called Jack to return a box of his belongings. When he requests to meet for coffee, she nonchalantly suggests he find her if he ever travels to Paris. Undeterred, Jack races after her to the airport, where he passionately recounts memories of their life together and their potential family. Intrigued by his heartfelt recounting, she eventually agrees to join him for coffee. From a distance, the two are seen animatedly engaged in conversation, laughter filling the air as they share this moment.
