Enid and Alfred Lambert are an elderly couple living in the small, midwestern town of St. Jude. Their days are filled with boredom, loneliness, and bickering over Alfred’s hoarding and Enid's attempts to redecorate their overcrowded home. In an attempt to break up the monotony, and take Alfred’s mind off of his deteriorating body, they plan a cruise with Nordic Pleasurelines. The boat takes off from New York City, so they fly there to visit their middle-aged son Chip. From his parents' point of view, Chip's life in the big city is scandalous. He reluctantly picks them up from the airport. From the second they are reunited, bickering and passive-aggressive arguments start, showing the obvious divide between son and parents.
Chip takes them back to his apartment, where surprisingly, his girlfriend Julia greets them. It quickly becomes apparent that she is just gathering her things to leave, so Chip follows her out. She berates him for his recent screenplay, revealing that the writing is overly focused on a young co-ed’s breasts, and leaves in a taxi. Worried that he has lost not only his girlfriend, but any chance he had at getting his screenplay produced by his girlfriend's boss, he starts down the street. While angrily stomping through the rain and flooded streets, he reminisces about his days as a professor which in part inspired his screenplay. He taught critical theory to uninterested students, only to have his whole world-view shaken by a freshman named Melissa. He went on a journey of self-discovery in Scotland, then came back and had a drug-induced affair with Melissa. This led to him being fired, and having to rely on loans from his little sister. His parents know nothing of these incidents.
Once Chip finds Julia's boss Eden, she brushes off his questions about the movie script and whisks him into a room where Julia’s husband Gitanus Misevicius sits. Gitanus and Eden proceed to rope Chip into a job working as a public-image and financial consultant of sorts for Gitanus. Gitanus persuades Americans to invest in Lithuania, flattering donors by naming streets after them or hanging their portraits in museums. Excited by the $3,000 cash that Gitanus gives him in advance for the first three weeks of work, Chip packs up his things and gets on a plane headed for Lithuania.
In Pennsylvania, Chip’s brother Gary lives with his wife Caroline and their three sons. He worries that he suffers from clinical depression, based on the symptoms of depression he reads about in Caroline’s self-help books. The tension in the household is palpable, with Gary trying to juggle both his mother and wife’s stubborn desires. The main argument centers around the coming Christmas; after an incident many years ago in St. Jude, Gary promised Caroline that they would never go back there for Christmas, but now Enid is insistent that they come because of Alfred’s failing condition. Neither woman will give any room on the issue, and Gary’s stress at being caught in the middle only worsens his depression. Additionally, Gary's father wants to sell an old patent to the Axon Corporation for $5,000, when Gary knows that it is worth at least twenty times that. Unable to convince his father to hold out for more money, Gary investigates Axon and tries to buy shares in it himself.
Gary attends an Axon presentation for future investors with his sister Denise. Denise successfully reserves a spot for Alfred in the Parkinson's-rehabilitation program, but Gary is unable to secure more Axon shares. Meanwhile, on the cruiseship Gunnar Myrdal, Alfred has vivid nighttime hallucinations about his feces coming to life, attacking, and mocking him due to his fears around his own incontinence. Alfred and Enid spend their days chatting with other couples on the Scandinavian cruiseliner, seeing shows, and gambling. Enid becomes friends with a woman named Sylvia Roth, whose daughter was recently murdered. The murderer has received the death sentenc and is set for execution in two days. Due to Alfred’s nighttime hallucinations, Enid is unable to sleep. She goes to the ship’s doctor and is given a supply of an experimental drug called Aslan to help. The next morning, when Enid is attending a financial seminar with a friend, she looks out the window and sees Alfred falling through the air. Alfred has fallen while leaning over the edge of the ship, careening down eight stories and landing in the water with a slew of injuries. The cruise is delayed so a helicopter can bring him to a hospital.
When Denise gets the call about her father, she has just been fired from her job as chef at a critically acclaimed restaurant called the Generator. She started the restaurant with a man named Brian, whom she almost had an affair with in the past before terminating it. She instead started sleeping with his wife, Robin, but he eventually found out, ending both Denise’s best job to date and the most recent in a string of failed relationships. She attempts to get Chip to come back for Christmas because of Alfred’s worsened condition, but he only agrees once the situation in Lithuania takes a turn for the worse. With a rival “crime lord” gaining power of the government and police force, and riots breaking out in the streets once utilities start to fail, Gitanis convinces Chip to flee. He gives Chip the money for his share of Lithuania and drops Chip at the airport, only to find that it has been shut down. They try and drive across the border instead, but are robbed at gunpoint by ski-mask wearing “police” force. Afterwards Chip walks 15 kilometers alone to the border, where he gets on a plane and makes it to St. Jude on Christmas.
Gary had arrived in St. Jude nearly a week before Christmas, without the rest of his family, much to Enid’s disappointment. It soon becomes apparent to him that Alfred’s mental ailments are even worse than his physical ones, with his dementia and hallucinations making life almost unbearable for everyone in the house. Denise arrives a few days later, and the two of them fight over Enid’s right to keep taking the addictive but helpful drug Aslan and about Alfred’s future. When Chip shows up on Christmas morning, an hour before Gary has to leave for his flight home, everyone but Enid is shocked. Gary’s built up resentment and anger finally boil over, and he yells at everyone about having to face the fact that Alfred can’t continue to live in the house, before he storms out.
Later, Alfred is seen in the midst of another vivid hallucination, this time believing that he is in a prison yard and other inmates are trying to kill him. He is snapped out of it by Chip, revealing that the inmate he was terrified of is actually his nurse, and he is in a nursing home. Alfred is panicked, and begs Chip to bring him home, but Chip says he can’t. Alfred is eventually transferred to a permanent nursing home, where two years later he dies after refusing to eat. His family appears more relieved than sad, with Chip living in Chicago with a new wife and kids, Enid visiting Denise in NYC, and Gary no longer fighting as much with Caroline. After Alfred’s death, Enid says that she found new hope for her life and has the desire to make some changes.
