Anders is a recovering drug addict residing in a rehab clinic in Oslo. During his first chance for an overnight leave, he encounters an old flame, Malin, which triggers dark thoughts that lead him to consider suicide. Filled with despair, he walks into a lake, but ultimately decides against it, returning instead to his rehab center where he remains silent about his attempt during group therapy.
On 30 August, Anders is granted a day off for a job interview in the city center. He makes a stop to visit his friend Thomas, his wife Rebecca, and their two children. Over the visit, he confesses to Thomas that after seeing Malin, he felt completely indifferent, admitting he never truly loved another ex-girlfriend, Iselin. As the conversation unfolds, Anders reveals his battle with suicidal thoughts, feeling overwhelmed at 34 and unsure about starting anew. Despite witnessing Thomas's happiness, he learns that Thomas also grapples with his own struggles, like losing passion for his marriage and facing dwindling friendships as he ages. Their parting is amicable, but Thomas urges Anders to refrain from rash actions while inviting him to a celebration later that evening hosted by mutual friend Mirjam.
Before his job interview, Anders places a desperate call to Iselin, leaving a voicemail pleading for her to return his call. When questioned about his résumé gaps during the interview, he openly admits to being a former drug addict, which visibly discomforts the interviewer. Feeling the weight of his past, he abruptly cuts the interview short, leaving with his application and tossing it aside in frustration.
He makes plans to meet his sister, Nina, but is caught off guard when her girlfriend, Tove, arrives instead. Tove reveals that Nina is avoiding him due to her struggle with Anders’s presence outside of rehab. Tove is meant to accompany him to their family home, but Anders, upset, rejects her offer and takes the keys to go alone.
Later, at Mirjam's party, Anders hopes to see Thomas but instead encounters friends who are unaware of his recovery, leading him to drink and quickly break his sobriety. During the celebration, which marks Mirjam’s birthday, they discuss the challenges of aging, leading to an awkward moment when Anders kisses Mirjam to console her. Retreating to another room, he calls Iselin again, leaving a message questioning her feelings for him and expressing a desire to reconnect, before resorting to theft from the partygoers’ possessions out of desperation.
Anders then visits his former drug dealer, purchasing heroin. Later at a bar, he connects with a friend and two young women, only to spot a man who had an affair with Iselin. In a moment of rawness, Anders forgives the man for the past but receives nothing but anger in response regarding his treatment of Iselin.
As the night progresses, Anders joins the group in a wild celebration, culminating in a midnight swim at a local pool, where he declines to join in the fun. Eventually, Anders returns to his family's home, which is chaotic and on the brink of being sold. In a moment of clarity, he reaches out to Iselin one final time, retracting everything he said before, and subsequently retreats to his childhood room where he succumbs to his addiction once more.
