The film begins with Thelma Post (June Squibb), a spirited 93-year-old widow who navigates the complexities of modern technology, with her grandson Danny (Fred Hechinger) passionately trying to educate her on the intricacies of the internet. Despite their loving bond, Thelma often feels that Danny dotes on her excessively, arguing that he needs to embrace more responsibility for his own life as he contemplates his future.
An unexpected twist occurs when Thelma receives a phone call from an unknown number. The caller, who claims to be Danny, informs her that he has landed in jail after an unfortunate car accident. He mentions that someone else will contact her soon, and moments later, another mysterious number calls. This person demands that Thelma deliver a staggering $10,000 to an undisclosed location to secure Danny’s release. Anxiety quickly overwhelms Thelma as she attempts to reach Danny, only to discover he doesn’t answer.
Seeking assistance, Thelma contacts her daughter Gail (Parker Posey) and son-in-law Alan (Clark Gregg), but they remain unreachable. Undeterred, Thelma collects the money and drops an envelope at the post office. Once Gail hears Thelma’s harrowing account, she urgently reaches out to Danny, who finally picks up the phone. The family gathers to visit the post office, hoping to recover the package, but they face a frustrating dead end as Thelma struggles to recall the address she sent it to.
As Thelma grapples with the realization that she has been scammed, her family rallies around her, wanting to provide support. However, Thelma refuses to surrender to the circumstances. In her quest to seek out help, she attempts to reconnect with friends, but finds most have either passed away or moved on. After some digging, she recovers the address she sent the package to, prompting her to ask Danny to accompany her to a nearby retirement home where her friend Ben (Richard Roundtree) resides. Despite Ben's efforts to reconnect, Thelma has kept her distance since the passing of her beloved husband, Teddy.
Upon reaching the retirement home, Thelma finds Ben preparing for a performance of "Annie." She explains her predicament, and Ben offers his help. Intrigued by Ben's bright red scooter, Thelma hops on, only to accidentally initiate a comical escape attempt, leading to a chase that results in a hilarious and heartwarming adventure. As the duo escapes, Danny realizes his grandmother is missing and alerts his parents.
Meanwhile, Thelma and Ben make a detour to visit their forgetful friend Mona (Bunny Levine) to obtain a gun to aid in their caper. While navigating Mona’s home, chaos ensues—a cockroach startles Thelma, resulting in a gunshot that adds an absurd twist to their escapades. As Danny searches desperately for his grandmother, he confers with the retirement home's staff—Rochelle (Nicole Byer) and Colin (Quinn Beswick)—who inform him of Thelma’s recent memory issues.
Through social media sleuthing, Danny discovers a telltale Instagram photo revealing Thelma’s whereabouts at a gas station. Thelma and Ben prepare to leave but spot Danny approaching, prompting them to hide stealthily. In a daring move, Thelma discards her LifeLine bracelet to obstruct tracking efforts, resulting in comedic tension as the family veers to follow a false lead.
As their adventure unfolds, Thelma and Ben find themselves in a gritty neighborhood. Friction arises between them as they confront Thelma’s tendency to push away the remaining connections in her life. The situation escalates when Ben’s scooter is damaged, ultimately prompting him to return to the retirement home. Undeterred, Thelma decides to march onward, only to stumble and struggle to rise—a poignant moment that underscores her resilience.
When Ben returns to lend assistance once more, they finally locate the UPS store related to her scammed money. They wait anxiously for the mysterious young man Michael (Aidan Fiske) to reveal the contents of the PO box. In a bold confrontation, Thelma demands the return of her funds from Michael's grandfather Harvey (Malcolm McDowell), who defensively rationalizes his actions given his dire financial straits.
In a thrilling turn, Thelma brandishes the gun, and an intense negotiation ensues. With Danny guiding her through the phone, Thelma secures her money but asserts her independence by parting with $500 for Harvey, squaring the score and leaving a lasting mark of her defiance in the face of wrongdoing. As she dramatically shoots his computer out of rage, a cascade of dramatic explosions occurs in her wake, symbolizing her fiery spirit.
In a heartfelt conclusion, Danny picks up Thelma and Ben, taking them back to a warm embrace from Gail and Alan. Together, they witness Ben’s performance, gathering for a touching family moment. Later, Danny brings Thelma to visit Teddy’s grave, where she expresses optimism about his future, underscoring the film’s emotional depth.
The credits roll with a touching tribute to Thelma, the real-life inspiration for the film, evoking a bittersweet reflection on life, love, and the enduring human spirit. The film is a heartfelt homage that resonates with audiences, leaving them to ponder their relationships and the values we hold dear. For Thelma serves not only as an entertaining tale but also as a tribute to the wisdom of the elderly, beautifully depicting their adventures and affirming their capacity for resilience against life's challenges.
