Former CIA black ops agent Frank Moses, played by Bruce Willis, has settled into a quiet suburban life where he often finds himself tearing up his pension checks just to engage in phone conversations with Sarah Ross, a charming call center employee who has captured his heart. However, the peace of his retirement is shattered when an assassination squad invades his home, prompting Frank to swiftly eliminate the attackers with his formidable skills. Recognizing that his phone calls with Sarah might have been monitored and fearing for her safety, Frank takes a drastic step — he travels to Missouri to rescue her, even resorting to kidnapping when she initially refuses to accompany him.
Meanwhile, CIA agent William Cooper, tasked by his superior Cynthia Wilkes, is assigned the mission to eliminate Frank. As Frank and Sarah navigate this dangerous situation, they find themselves in a motel room in New Orleans where Frank, with Sarah tied up momentarily for her own safety, seeks the assistance of his former mentor, Joe. Ignoring the risks, Joe provides crucial intelligence indicating that the same squad that targeted Frank was also responsible for the murder of a New York Times reporter. However, Sarah manages to escape and inadvertently alerts Cooper with a 9-1-1 call, leading to a tense confrontation where Frank narrowly saves her from one of Cooper's agents.
In New York, Frank and Sarah visit the mother of the slain reporter. This meeting introduces them to a list of names connected to the investigation into the reporter’s death, revealing that almost everyone on the list has been killed — including Frank. On a distressing note, Joe's retirement home room is breached, leaving Frank heartbroken after learning of a hitman's intrusion.
Determined to uncover the truth, Frank and Sarah locate retired agent Marvin Boggs, whose name is adjacent on the list. They discover chilling details surrounding a series of killings linked to their past in Guatemala from 1981. The trio’s investigation leads them to pilot Gabriel Singer, who is tragically shot by a sniper before he can divulge any vital information. To further their mission, Frank enlists the help of retired FSB agent Ivan Simanov in exchange for a future favor and, accompanied by Sarah, infiltrates the Secure Records Vault at the CIA headquarters in Virginia with the intention of retrieving the Guatemala file.
Their mission faces a sudden challenge when Cooper confronts Frank in his office, leading to a ferocious struggle that ends with Cooper being disarmed but not before he inflicts an injury on Frank. Eventually, Frank and Sarah are rescued by Marvin and Joe, who had miraculously survived the earlier attack. Together, they seek the expertise of retired British assassin Victoria Winslow to assist in confronting Alexander Dunning, the sole survivor on their list of individuals connected to the covert operations.
During a steely interrogation at Dunning's home, it is disclosed that the killings were orchestrated by U.S. Vice President Robert Stanton to hide his involvement in the massacre of innocent villagers during the Guatemala incident. As tensions rise, Cooper's investigation leads him to Dunning’s mansion, but when chaos ensues, Joe heroically sacrifices himself to give Frank and Marvin a chance to escape.
In a dramatic turn of events, Frank's group captures Stanton, using the leverage to negotiate Sarah's freedom. A tense exchange occurs when Cooper arrives, resulting in Dunning's betrayals unfolding as he tries to manipulate Cooper into turning against Frank. However, in a shocking twist, Cooper instead eliminates Cynthia and a fierce confrontation with Dunning and his bodyguards ensues, leading to dramatic conclusions for several characters involved.
With their ordeal behind them, Frank and his companions plot a new adventure as they prepare for their next mission in Moldova, where Sarah insists on joining Frank, culminating in an exhilarating scene where they are seen evading Moldovan troops with a stolen nuclear device.
