Judd Altman, portrayed by Jason Bateman, discovers that his wife Quinn, played by Abigail Spencer, has been involved in an affair with his boss Wade, brought to life by Dax Shepard, for an entire year. After moving out, he gets a call from his sister Wendy, played by Tina Fey, who informs him that their father Mort has passed away. The Altman family gathers at their mother's home for the funeral, where tensions and unresolved feelings bubble to the surface.
During this time, Wendy reconnects with her ex-boyfriend Horry Callen, played by Timothy Olyphant, who suffers from the effects of a brain injury. Meanwhile, Judd meets up with his older brother Paul, depicted by Corey Stoll, and Paul's wife Annie, played by Kathryn Hahn, who happens to be Judd's former girlfriend. The youngest brother, Phillip, portrayed by Adam Driver, arrives late with his new, significantly older girlfriend Tracy, played by Connie Britton.
The matriarch, Hilary, brought to life by Jane Fonda, informs her children that despite being an atheist, Mort wished for them to observe shiva, with their childhood friend Rabbi Charles "Boner" Grodner officiating. Unbeknownst to the rest of the family, Wendy is the only one aware of Judd's marital crisis. Judd also rekindles a connection with Penny Moore, portrayed by Rose Byrne, who had a crush on him during their high school days.
As the family grapples with grief and dysfunction, an intoxicated Wendy urges Judd to confront Quinn's betrayal. Phillip expresses his frustrations about being perceived as the family misfit while flirting indiscriminately. In a moment of vulnerability, Judd admits to everyone that Quinn has been unfaithful and that he's contemplating a divorce. Just as they are processing this revelation, Quinn shocks Judd by announcing that she is pregnant. When Phillip learns about the pregnancy, he inadvertently spills the news to the rest of the family.
Following his night with Penny, Judd finds himself navigating a complex web of emotions as Wendy seeks closure with Horry. As the tension mounts, the brothers sneak out of temple to indulge in some hidden marijuana discovered in their father’s suit. In a complicated turn of events, Annie attempts to seduce Judd, believing that he may help fulfill her desire for a child, but he turns her down. This rollercoaster of emotions culminates in Wendy sleeping with Horry, reigniting old feelings.
Quinn ultimately calls Judd in distress, fearing a miscarriage, compelling him to rush to the hospital, where Wade also makes an appearance. Amidst the chaos, the baby girl is born, leading to a fight between Judd and Wade in the hospital waiting room. Wendy retaliates by punching Wade, and a group of young bystanders, witnessing the confrontation, help Judd vandalize Wade’s car. Wade, overwhelmed and unsure of how to step into fatherhood, ultimately leaves Quinn.
The next day, Tracy parts ways with Phillip, leading to further dynamics within the family. Judd makes efforts to reach out to Penny, but is met with resistance. Annie expresses her frustrations to Judd, who gently reminds her of the love and family they already have, only for Paul to misinterpret their closeness and attack Judd in a fit of jealousy. In a surprising twist, Hilary confronts the family by kissing Linda passionately, announcing their romantic relationship and revealing that Mort had encouraged their union, using shiva as an opportunity for the family to reconnect.
As the story unfolds, Judd’s emotional turmoil leads him to an electric shock incident while fixing the fusebox, triggering memories of his father. This moment catalyzes his grief process, allowing him to finally mourn Mort's absence. Judd expresses his sincerest apologies to Penny, realizing they share profound feelings for one another, culminating in a passionate kiss that solidifies their bond.
Wendy ends her connection with Horry yet again, moving forward with her children, while Judd and his brothers reconcile their differences. Paul generously offers Phillip a job in their late father's sporting goods store, signaling a new beginning for the siblings. Quietly, Judd steals Phillip's Porsche and embarks on a road trip to Maine, fulfilling a long-held dream of escape.
