The Fang family's peculiarities surface again when Baxter (played by Jason Bateman) audaciously snatches a teller's lollipops, compelling Caleb to take action and become a makeshift security guard. Their mother, Camille (portrayed by Nicole Kidman), pretends to sustain a fatal injury, while Annie (brought to life by Kathryn Hahn) mournfully pays tribute to her supposed passing. Just before leaving, Caleb delivers a heartfelt eulogy celebrating life, wrapping it up with a dramatic flourish of his bow.
In a subsequent scene, Annie, now an adult, finds herself on a film set where she is pushed to reveal her skin for the director’s vision. Hesitant at first, she ultimately returns to the set lacking attire, only to have her vulnerability exploited by an intrusive crew member. The resulting photograph is sold to a tabloid, casting her in a deeply unfavorable light.
Meanwhile, Baxter grapples with the repercussions of his previous creative choices. After publishing two novels, he embarks on a new career documenting the art of potato gunsmithing. As he dives into this unexpected endeavor, his fascination with the subject grows, leading him to invite his subjects into a misguided game of William Tell, resulting in an unfortunate trip to the hospital.
As the Fang family comes together once more, they all share a sense of disillusionment. Caleb strives to unite his siblings in a fresh performance art piece, but Annie stands firm in her decision to abstain, frustrating Caleb. In a further display of creative void, Baxter attempts to film the chaos at a food court, where he hands out fake coupons for free chicken sandwiches. To Caleb’s dismay, Annie's generosity knows no bounds as she freely offers the coveted items to anyone who asks.
During this artistic lull, Annie finds comfort in watching old recordings of their previous performance art projects. A documentary featuring their parents unveils memories from their early avant-garde endeavors, highlighting Caleb's cringeworthy attempts, like the disastrous crossbow incident involving Hobart. The siblings also recall a memorable busking experience in Central Park, belting out tunes such as "KAP (Kill All Parents)" to a confused audience.
Later on, Annie discovers a hidden compartment within her childhood wardrobe, unveiling a series of intriguing postcard-sized paintings. As she and Baxter inspect the artwork's quality, Camille suddenly appears, frantically trying to hide the pieces. Her reasoning—to keep it from Caleb, who might not approve of her artistic freedom—only highlights the intricate dynamics within the Fang family.
Following the fallout from their failed chicken sandwich prank, Caleb and Camille decide to take a short retreat to the picturesque Berkshires. However, their disappearance triggers a police investigation when their vehicle is found with an unsettling crimson smudge on the dashboard. Annie's attempts to calm everyone with the notion that the blood is merely part of Caleb's creative expression do little to ease tensions. Baxter remains skeptical, spiraling into resignation as anxiety mounts. As time passes, Annie becomes obsessively determined to uncover the truth behind their vanishing act.
A nostalgic reflection takes Annie back to her high school days, recalling the drama of her senior production of Romeo and Juliet, marred by the sudden absence of her Romeo. Baxter, who was cast as the understudy, hesitated at a crucial moment, causing a cringe-inducing reaction from the audience and leaving Annie utterly humiliated. The fallout led to the expulsion of Miss Delano, the drama teacher, only for Annie to realize later that Caleb's elaborate scheme had been worth the trouble.
As Annie and Baxter confront the unsettling reality of their parents' true selves, horror sets in with the realization that Caleb had little interest in fatherhood until he discovered that his children served as living art. This revelation triggers disquieting questions about their family dynamics.
In an unforeseen twist, Annie and Baxter comb through the remnants of a yard sale at their parents' house, during which they uncover a CD by the Vengeful Virgins featuring a haunting cover of "KAP", a song familiar only to the Fangs. As they probe deeper, they track down the teenage twins responsible for the music and put them through an intense interrogation while Baxter investigates their parents’ residence, unearthing disturbing footage of Caleb smearing blood in the car.
Just as tensions hit a breaking point, Miss Delano returns, unveiling her true role as the twins' mother. Caleb appears, equally reluctant as Baxter to partake in this final act of their grand scheme. The truth slowly emerges: Camille has been maintaining a double life, living as a widow part-time in a small town, while Caleb and Miss Delano have long operated under various identities.
With the shocking revelation that their parents' latest charade has been in the works for years, Annie and Baxter are forced to acknowledge their roles as mere pawns in a convoluted plot. As they grapple with the reality of their family's twisted nature, they reluctantly agree to help maintain the secret, their resentment softened only by a flicker of relief.
Following this astounding revelation, Annie and Baxter begin finding their balance, ultimately learning to release their grip on their parents’ legacies.
