High-achieving high school student Joel Goodsen finds himself navigating the complexities of adolescence in the upscale Chicago suburb of Glencoe, where his wealthy parents reside. With aspirations for him to attend Princeton University, his father, an alumnus, encourages Joel to join the Future Enterprisers program, which helps students create small businesses.
When Joel's parents head out of town, his adventurous friend Miles persuades him to seize the opportunity for some lighthearted escapades. That first night, Joel indulges in his freedom—raiding the liquor cabinet, blasting music, and even joyriding in his father's car while dancing in his undergarments to the classic tune "Old Time Rock and Roll".
The following day, Miles facilitates a rather questionable encounter by calling a prostitute named Jackie for Joel. To his surprise, Jackie is a male cross-dresser, which prompts Joel to pay him to leave. However, Jackie ultimately provides Joel with the contact for another escort, Lana. When Joel nervously calls her that evening, he is captivated by Lana's stunning beauty, leading to a night of passionate intimacy.
The next morning brings an unexpected dilemma as Lana requests $300 for her services. After a trip to the bank, Joel returns to find her gone, along with his mother’s prized Steuben glass egg. Desperate to retrieve it, Joel tracks down Lana, only to confront her intimidating pimp Guido, who threatens him with a gun. In a tense chase involving Joel's father's Porsche 928, he narrowly escapes Guido's wrath.
Lana reveals that her valuable possessions are at Guido's place, which prompts Joel to allow her to stay at his home while he attends school. Upon returning, Joel is surprised to find his friends gathered, and although Lana suggests inviting another escort, Vicki, he declines. The situation escalates when Guido confronts the women outside Joel’s house, prompting a chaotic scene that forces them back inside. Despite the tension, Joel eventually agrees to let them stay for one more night.
Later that evening, a relaxed vibe settles as Joel, Lana, Vicki, and Joel’s friend Barry indulge in marijuana. Their carefree demeanor leads to an unfortunate mishap—while retrieving her purse, Lana accidentally nudges the Porsche out of gear, sending it careening down a hill and into Lake Michigan, where the car sinks following the pier's collapse.
When Joel takes the car to a repair shop, he’s hit with the grim news of the exorbitant repair costs. In a moment of desperation, he and Lana concoct a plan to transform his parents' home into a temporary brothel for one night to raise funds. The raucous party draws in a crowd of Joel’s classmates and Lana's colleagues, resulting in a lucrative venture.
However, fate intervenes as the evening coincides with a pivotal interview from Princeton recruiter Rutherford, who is there to assess Joel for admission. Despite the festivities, the interview is rife with distractions, leaving Rutherford unimpressed with Joel's qualifications. Nevertheless, he unwittingly becomes acquainted with Lana and her companions amid the party atmosphere. As the night winds down, Joel and Lana share an intimate moment on the Chicago "L".
Upon returning home after retrieving his repaired car, Joel is aghast to discover a burglary has occurred in his absence. When he attempts to reach out to Lana, he finds Guido at the other end, who informs him he could buy back his stolen furniture. In a race against time, Joel and his friends manage to restore the house just as his parents return, though his mother quickly spots a crack in her beloved egg. Ultimately, Joel's father praises him for impressing the Princeton interviewer, ensuring his acceptance into the prestigious university.
In a concluding meeting at a restaurant, Joel shares a moment with Lana, where they ponder the potential of their relationship. With a playful grin, he quips that continuing to see each other may come at a cost, hinting at the uncertain path ahead of them.
