As he enters his house, Gabe Goodman, a teen, is surprised to find his mother, Diana, awake at 3:30 AM. Diana answers that for the past week, she has been sitting up imagining possible death scenarios for Gabe to account for him getting home late each time. Gabe tries to get her to stop worrying, but they are interrupted when Gabe’s father, Dan, overhears talking in the house and comes down to investigate. Diana sends Gabe upstairs another way, prompting Gabe to wonder why Dan hates him. When Dan asks if Diana is okay, Diana assures him she will be up shortly to have sex.

Privately, Diana asserts that she loves her “perfect” family, even though her son, her husband, and her daughter all have their own flaws (“Just Another Day”). Diana’s teen daughter, Natalie, enters the room with schoolbooks and a Red Bull. Seeing how inundated Natalie is with work, Diana advises her to set aside personal time for herself, then excuses herself to have sex with Dan. Privately, Natalie laments that her family fakes loving each other. She wonders if other families are like hers. She and Gabe comment that this is the normal pace of life in their household, though Gabe is more optimistic about that pace than Natalie.

After they finish having sex, Dan rushes to get ready for work. Diana quips about his mediocre sexual performance, but because Dan doesn’t hear it, Diana feigns enthusiasm with him. Privately, Dan admits that he doesn’t understand Diana and that he’s barely keeping their family together. Dan and Diana wonder if they can maintain a stable grasp on their lives. The whole family observe that they can endure the pain of their respective issues, so long as it doesn’t kill them.

The family gathers in the kitchen. Diana urges Gabe to get his day started because of all the extracurricular clubs and sports he has to attend. Natalie asks Diana if the family will be able to attend her winter recital. Diana indicates that she will put it on the calendar, but then Natalie observes that they haven’t updated their family calendar in months, since it is still stuck in April of the previous year. Dan asks Diana if she can take care of the groceries since work has been extra heavy for him lately. Diana answers him like a cavewoman, reminding him of their household roles. Dan doesn’t understand. 

Dan, Natalie, and Gabe get ready while Diana prepares sandwiches. Soon, the family notices that Diana has made too many sandwiches and that the ingredients are spilling over to the floor; Diana repeats that she is determined to keep their family stable, even if the world keeps moving at a dizzying pace. Dan stops Diana. Natalie and Gabe watch her with concern. Their parents urge them to go catch the bus. Dan helps Diana clean up the mess. He suggests that they should go see Doctor Fine.

At school, Natalie uses her free time to practice her recital piece (“Everything Else”). She comments that many people thought Mozart was “crazy,” but they just couldn’t understand his technical genius. Whenever she plays the piano, she feels her sense of the world slip away. She wants to perfect her musical skill so that she can get a full scholarship into Yale and get away from her parents, which she feels will make her feel better about all the effort she’s put into school.

Natalie sees that a boy named Henry is watching her play. Henry compliments her performance and introduces himself as her classmate in several classes. He knows that Natalie goes to the music room to play for seven minutes before and after school starts. When Natalie comments that his awareness is creepy, Henry prepares to leave her alone. Natalie advises him not to give up on talking to her. Henry is confused by her behavior, which Natalie suggests is not as bad as her mother’s.

At the clinic, Doctor Fine runs through a long list of medications that Diana has to take (“Who’s Crazy/My Psychopharmacologist and I”). Dan wonders whether Diana is “crazy” because of her mental illness or if he is “crazy” because he continues to hope that Diana will work through her illness. Dan remembers falling in love with Diana when they were in their early 20s, but now he just wishes Diana could drive herself to the clinic. 

Diana describes her relationship to Doctor Fine as an “odd romance,” highlighting the uneven exchange of knowledge they have with each other. Doctor Fine knows all of Diana’s secrets and will always offer emotional availability to her, but she cannot rely on him as she might rely on a romantic partner. Doctor Fine records his case notes, explaining that Diana has bipolar disorder, depression, and episodes of delusion. Though Diana has undergone medication for 16 years, she and the doctor have yet to find a medication regimen that can best help her while inducing minimal side effects.

Back in the school music room, Natalie asks Henry about his penchant for jazz, which she cannot understand because of its spontaneity. Henry’s explanation causes Natalie to deduce that Henry regularly uses drugs. Henry stresses that he likes improvisation more than composition, with Natalie sarcastically applying improvisation to Mozart’s composition method. They continue bonding over their differences in musical styles.

Doctor Fine and Diana discuss the adjustments to her medication regimen, with the doctor warning her about the various side effects, including death. After several weeks of adjustments, Diana loses her sex drive, which Doctor Fine blames on the medication. All the while, Dan continues to sit in the car, wondering whether he has wasted his life hoping for Diana to work through her mental illness. He feels exhausted. On the seventh week of medication adjustment, Diana indicates that she has lost all sensation of feeling. Doctor Fine suggests this is a sign that she is “stable.”

Henry and Natalie spend time together in Henry’s room. Henry smokes from a bong, then offers it to Natalie, but Natalie declines. Henry tries to kiss her, but Natalie pulls away, explaining that she feels that a single mistake could ruin her life. Henry tries to reassure her that her life isn’t on the verge of disaster. Natalie doesn’t believe him because he has taken drugs.

Henry stresses his point, citing the state of the environment, which he thinks is on the brink of disaster (“Perfect for You”). Ultimately, he is saying this as a pretext to confess that he loves her and that he thinks he can be the perfect partner in this kind of world. Even if he isn’t perfect, he resolves to adjust to her needs. Natalie agrees to enter a relationship, reciprocating Henry’s belief that she could be perfect for him too. They kiss. When Henry drops Natalie off at home, he asks if he can come inside. Natalie bluntly refuses.

Diana and Gabe watch Natalie from inside the house. Diana cannot believe she failed to notice that Natalie was seeing someone. When Gabe suggests how easily teenagers can fall in love, Diana has a flashback to when Dan asked her to marry him when he was still 21. It is implied that Dan asked this after Diana unexpectedly became pregnant. In the past and in the present, Diana hears echoes of Dan’s optimism in Henry’s reassurance of Natalie. Diana sees Natalie and Henry kiss. Natalie returns inside, then rushes up when she sees that Diana has been watching.

Diana feels nostalgic about her past self, remembering that she was passionate and ambitious when she was young, but has become lost and listless in the present (“I Miss the Mountains”). Though she remembers the challenges of working with her mental illness when she was younger, she still misses the sense of adventure her youth gave her. She disposes of all her medications in the toilet. Gabe encourages this instinct, indicating that Dan doesn’t have to know what Diana is doing.

Time passes. Dan is optimistic with the way things have turned out, especially since he hasn’t had to attend to any emergencies over the past few weeks (“It’s Gonna Be Good”). Diana has kept herself preoccupied with housework, which Dan takes as a sign that she is happy. Meanwhile, Henry takes Natalie home and wonders when he’ll get to meet her family, seeing as they’ve been dating for over two months already. Dan catches them on the porch and invites Henry in for dinner. Natalie looks for excuses to stop Henry from meeting the rest of the family, but Henry enthusiastically accepts Dan’s invitation. 

Diana excitedly serves dinner, which ends with her bringing out a birthday cake. Henry is surprised when Natalie reveals that the birthday cake is for her brother, who died before she was born. Diana registers everyone’s shocked expressions. Dan tries to tell Diana that Gabe isn’t with them anymore, reminding her that he died many years ago (“He’s Not Here”). This upsets Natalie, who curses as she storms out. 

Diana admits to Dan that she disposed of her medication. Dan assures her that he knows that she is experiencing something difficult. This upsets Diana, who enumerates the private challenges she faces each day, including ideation of death and having to face the terror of her life. She accuses Dan of not knowing how she feels, considering that he never shows his pain and finds it easy to tell her to move on.