Teachers Martin, Tommy, Peter, and Nikolaj are colleagues and friends that work at a gymnasium school in Copenhagen. All four struggle with unmotivated students and feel that their lives have become boring and stale. At a dinner celebrating Nikolaj's 40th birthday, the group begins to discuss psychiatrist Finn Skårderud, who has theorized that humans are born with a blood alcohol content (BAC) deficiency of 0.05, and that attempting to maintain such a BAC makes one more creative and relaxed. While the group initially dismisses the theory, Martin, who is depressed due to troubles in his marriage and job, is inspired and starts to drink at work. The rest of the group eventually decides to join him, considering the ordeal an experiment to test Skårderud's theory. They agree to a set of rules: their BAC should never be below 0.05, and that they should not drink after 8:00 pm or on the weekends. Within a short period of time, all four members of the group find both their work and private lives more enjoyable. Martin, in particular, is delighted as he finally manages to reconnect with his wife and children. Agreeing that the experiment should be taken further, the group increases the daily BAC limit to 0.10. Still finding their lives improved, the group decides to attempt binge drinking to observe how their bodies and minds respond. A while into their experiment, the group has a fun night, but after coming home drunk, both Martin and Nikolaj are confronted by their families. Martin's family express their worries that he is descending into alcoholism, revealing that he has been visibly drunk for weeks. After a heated argument during which Martin's wife admits to infidelity, Martin leaves her. The group abandons the experiment. Months later, all the members of the group have stopped drinking during the day with the exception of Tommy, who has become an alcoholic. A few days after his dismissal due to arriving to work drunk, Tommy boards his boat with his old dog, sails out on the ocean and dies, presumably by falling in (possibly by suicide, but this is not explicitly stated). The three remaining members of the group go out to dinner after Tommy's funeral and appear reluctant to drink the alcohol which is served. While dining, Martin receives a message from his wife who states that she is willing to give their marriage another chance, as the recently graduated students drive by. Martin, Peter and Nikolaj join them in celebrating and drinking at the harbour. Martin, a former jazz ballet dancer, dances with the rest of the partygoers, which he had refused up to this point in the film despite his colleagues' repeated urging. His dance becomes increasingly energetic and joyous, and the story ends as he leaps into the water, on a freeze frame of him in midair.