Frank Moses, portrayed by Bruce Willis, is a retired black-ops CIA agent enjoying a quiet life in Parma Heights, Ohio. Yet, loneliness shadows him, prompting frequent phone conversations with Sarah, a customer service representative played by Mary-Louise Parker, who works at his pension office in Kansas City. To sustain these conversations, Frank concocts schemes, like fabricating lost pension checks to draw her in.
His tranquil existence shatters one night when a skilled hit squad invades his home. In a desperate fight for survival, Frank takes down the intruders and quickly realizes his phone is being monitored, motivating him to rush to Kansas City to safeguard Sarah. Although initially hesitant, Sarah becomes Frank's unexpected ally as he embarks on a mission to uncover the identity of those who want him dead, seeking the assistance of his old black ops colleagues.
Among those tracking Frank is CIA agent William Cooper, played by Karl Urban, who has been dispatched with orders to eliminate him. Frank's first move leads him to New Orleans, where he reunites with his ailing mentor, Joe Matheson, played by Morgan Freeman, now residing in a retirement community. Joe reveals that the same killer squad is responsible for the assassination of a New York Times journalist. This revelation propels Frank and Sarah on a thrilling quest, as they sift through clues left by the murdered reporter, uncovering a dangerous hit list.
Their investigation leads them to Marvin Boggs, a former black ops member portrayed by John Malkovich, whose paranoid nature complements his vast knowledge. Marvin informs them that all the names on the list tie back to a covert operation in Guatemala from 1981, implicating Frank and Marvin in a dark past. Gabriel Singer, played by [James Remar], is the last person alive tied to their mission. The trio tracks him down only to witness his assassination by a helicopter gunner just moments after he divulges the chilling truth: everyone on the list has been silenced.
In a high-stakes maneuver with the help of Ivan Simanov, a former Russian secret agent played by Brian Cox, Frank gains crucial intel and security access to the CIA headquarters. As they orchestrate a daring infiltration to retrieve vital files, chaos ensues; Frank finds himself wounded after a brutal confrontation with Cooper. Meanwhile, Joe narrowly escapes an assassination attempt and returns to help extract Frank and Sarah, the trio taking refuge at the home of former wet-work agent Victoria, played by Helen Mirren.
Upon reviewing the obtained files, the team faces a critical hurdle: identifying Alexander Dunning, played by Richard Dreyfuss, who remains unlisted but is pivotal to the mystery. Their investigation reveals a shocking cover-up involving Vice-President Robert Stanton, a young lieutenant whose past horrors have come back to haunt him as he attempts to erase witnesses in a bid for the presidency.
Tensions escalate when Cooper and the FBI encircle Dunning's estate, forcing Frank to negotiate his surrender. However, a tactical ploy involving Joe results in sacrifice; he pretends to give in but is ultimately gunned down by an unseen marksman, enabling the team to escape even as Sarah is captured. In a bold move, Frank contacts Cooper, threatening dire consequences for Sarah’s safety, while vowing to eliminate Stanton.
With their goals unified, Frank's team, including Ivan—revealed to be Victoria's former partner—embarks on a plan to infiltrate a gala in Chicago where Stanton is present. Despite Cooper's relentless pursuit, they manage to abduct Stanton and orchestrate a trade for Sarah's release. The encounter escalates into a brutal betrayal when Dunning’s true manipulative nature surfaces, leading to a violent confrontation that sees Cooper turning against his corrupt associates.
As alliances shift and the truth unfolds, the chaotic climax ensues with lives hanging in the balance. Ultimately, Cooper's decision allows Frank and his team to escape alive, as Frank and Sarah are left looking forward to a new beginning together.
The film concludes with an unexpected twist, showcasing Frank and Marvin on the run in Moldova, in a comedic scene involving a stolen nuclear device transported in a wooden wheelbarrow, with Marvin donned in a dress, providing a light-hearted finish to their intense adventure.
