Western intelligence agencies pinpoint the notorious Pakistani arms dealer and terrorist leader, Aamir Barkawi (Alon Moni Aboutboul), as the orchestrator behind a series of devastating terror attacks across the globe. Following the discovery of his compound, the United States launches a drone strike believed to eliminate both Barkawi and his family. However, two years later, Mike Banning (Gerard Butler), a dedicated Secret Service agent assigned to protect President Benjamin Asher (Aaron Eckhart), is eagerly anticipating the arrival of his first child with his wife, Leah.
Unbeknownst to them, Barkawi has survived the strike and, in Yemen, reunited with his son Kamran (Waleed Zuaiter) to plot a calculated revenge. The situation escalates when the news of British Prime Minister James Wilson's death reaches Asher and Banning. Alongside Secret Service Director Lynne Jacobs (Angela Bassett), they travel to London for Wilson's funeral, arriving safely via Air Force One at Stansted Airport.
As world leaders gather, a heinous assault unfolds with mercenaries working for Barkawi. The attack begins with a horrifying explosion that obliterates the Canadian Prime Minister's limousine, tragically killing him and his wife. The onslaught continues, claiming the lives of multiple leaders, including the Japanese Prime Minister, who drowns due to a engineered bridge collapse, and the French President, who falls victim to a bomb blast that severely damages landmarks like Big Ben.
Chaos engulfs the city as Asher, Banning, and the Secret Service engage in a desperate firefight outside St Paul's Cathedral, followed by a thrilling car chase with the disguised terrorists. The ambush claims heavy casualties on both sides. Ultimately, Banning, Asher, and Jacobs manage to escape to a secure location, but the terrorists disrupt the power supply, plunging London into darkness.
In a frantic attempt to escape via Marine One from Somerset House, disaster strikes as terrorists equipped with Stinger missiles shoot down their aircraft. The crash results in Jacobs receiving fatal injuries; her last wish is for Banning to avenge those killed. As Banning and Asher find refuge in the deactivated Underground system, the gravity of their situation becomes clear: capturing Asher alive is the terrorists' ultimate goal, and he instructs Banning to eliminate him if needed to avert a public execution.
With Asher’s life hanging in the balance, Banning contacts Vice President Allan Trumbull (Morgan Freeman) to relay their situation and the location of an MI6 safe-house. While the White House grapples with a menacing call from Barkawi, who reveals his plan and the poisoning of Wilson, Banning and Asher reach safety. However, a shocking twist reveals the presence of impostor rescue teams.
Banning soon realizes that the operators they hoped would save them are, in fact, terrorists infiltrating the British intelligence. As Jax heads to Scotland Yard to seek assistance, Banning remains behind to confront the threat directly. During an intense struggle, Asher is captured and taken to a construction site, where Kamran prepares to execute him live.
In a fierce showdown, Banning partners with elite SAS and Delta Force commandos to mount a daring rescue. Just as Kamran is about to deal a fatal blow, Banning crashes in, initiating a fight that leads to Kamran's escape amidst the chaos. With the option of remaining hidden no longer, Banning makes the critical decision to destroy the building, ensuring their safety and the demise of Kamran and his accomplices.
After revealing the traitor within MI5, Jax eliminates him, clearing a path toward resolution. Eventually, Barkawi's compound in Yemen is discovered, resulting in a final drone strike that neutralizes the threat.
Weeks after the turmoil, Banning cherishes quiet moments at home with Leah and their newborn, named Lynne, in loving memory of his fallen leader. Deeply moved by Trumbull’s stirring speech about the resilience of the United States, Banning finds the courage to reevaluate his commitment and ultimately decides against submitting his resignation.
