As Larry Burrows reflects on his 35th birthday, the seemingly ordinary day spirals into a whirlwind of comedic and dramatic escapades. This day serves as a poignant reminder of unresolved feelings stemming from his past, particularly the haunting moment from his 15th birthday — a missed opportunity during the state high school baseball championship game that left him with an unshakeable sense of regret. Consumed by a tumultuous stream of "what ifs," he finds himself wondering how different his life might be had he landed that pivotal home run.
In the midst of his mounting frustrations, Larry happens upon The Universal Joint, a dimly lit bar pulsating with pink neon lights. Exhausted and demoralized, he enters the establishment, hoping for a small reprieve as he awaits a tow truck to rescue his beloved Ford LTD station wagon from a dark alley. While there, he strikes up a conversation with bartender Mike (Jay O. Sanders), who emerges as a guardian angel of sorts, allowing Larry to unburden himself with stories of the catastrophes of his day. It is during this cathartic exchange that Larry learns of a nefarious scheme orchestrated by his department head, Niles Pender (the villain of the piece), who has made secret arrangements to sell their company to unsuspecting Japanese investors.
Longing for a chance to rewrite his own history, Larry's wish is suddenly granted when Mike serves him "The Spilt Milk," an extraordinary cocktail with otherworldly powers. With a single sip, Larry is whisked away into an alternate reality where his youthful dreams came true. In this vibrant new world, he finds himself ascending to the heights of success in a prestigious corporate position, married to the enchanting Cindy Jo Bumpers (the boss's alluring daughter), and enjoying the accolades of those around him. Initially, life appears idyllic, yet as he grows more accustomed to this alternate existence, the absence of his cherished connections — like his best friend Clip Metzler and his wife Ellen — begins to weigh heavily on him. Even more troubling, this new life has drawn out adversaries, such as Jewel Jagger, a sly secretary with ambitions of her own.
Stepping out of the bar, Larry is enveloped by the disorienting realization that someone has taken over the life he once knew. His once chaotic yard has morphed into a pristine sanctuary, and soon, Mike reemerges, now in the guise of a cab driver, to take him to a new home — a magnificent mansion in the upscale neighborhood of Forest Hills. As they drive, Mike drops a bombshell; he too hit the final baseball pitch, which entangled Larry in an unexpected twist of fate — discovering that Cindy Jo is now his wife, and he is the president of Liberty Republic Sporting Goods. His passion for classic cars is ignited as he uncovers a treasure trove of antique automobiles.
As Larry delves deeper into this bizarre new reality, he is struck by how drastically Clip's timid persona contrasts with the lively friend he once knew. Ellen, steadfast in both realms, is now committed to another, while Jewel has developed into an enchanting yet dangerous figure. When Larry reconnects with Ellen, nostalgia reignites their bond, and after some persuasion, they agree to a dinner date, allowing Larry to reminisce and share fond memories from their previous life.
However, Niles is not about to let Larry off easily; he schemes to inform Cindy Jo about Larry's dinner with Ellen, laying out a treacherous plan for confrontation at the office. Fate takes an unexpected turn when a surprise visit from Leo Hansen, the company owner, inadvertently shifts the scenario, leading to chaos and a miscalculation on Niles' part that results in Leo's demise instead. As the authorities arrive, chaos ensues, with Jewel's jealousy sparking turmoil outside, causing a chain reaction of events including setting several police cars ablaze. Caught in this chaos and facing an impending loss, Larry finds himself cornered before the familiar neon light of The Universal Joint beckons him back to the comforts of his earlier life.
Back amidst the unraveling mysteries, Larry is spared from police collision by a tow truck — driven by Duncan, heralding his full circle return to normalcy. Upon spotting Mike back behind the bar, relief washes over him as he acknowledges all that Mike has done throughout this tumultuous journey. Upon leaving, a startling revelation hits him; the sale to the Japanese investors is mere hours from completion. Defying the odds, Larry heroically storms into the boardroom, thwarting Niles just as Leo was ready to ink the deal.
Returning to his world, Larry is met with a surprise party thrown by beloved friends and family, complete with a driveway reflecting the messy nature of his journey. This joyous occasion, however, takes an interesting turn when Cindy Jo and her husband Jackie Earle, the company president, arrive to extend a tempting offer: Niles' position, along with a new Mercedes and company perks. With renewed hope, Larry embarks on a brighter path ahead.
Flashing back to a younger Larry, he still wrestles with the sting of lost victory at the stadium. It is there that he encounters the enigmatic Mike, who imparts words of comfort and wisdom, reminding Larry of the potential lying dormant within him. Though initially baffled by Mike's insights, he leaves grateful, pondering the mysteries of destiny and the unseen threads connecting their lives.
