As Jack Silva (John Krasinski) steps off the plane in Benghazi, he is greeted by his reliable colleague, Tyrone "Rone" Woods (James Badge Dale). This encounter, seemingly routine, rapidly escalates into a tense fight for survival. Their vehicle is halted by a group of militants demanding an impromptu inspection. With remarkable composure, Rone alerts their Chief (David Costabile) for assistance, only to be met with a firm refusal to intervene. In a show of bravado, Rone warns the militants that their actions are being watched by a drone, and not only are they at risk but their families as well. Eventually, the confrontation ends, and they are allowed to depart.
Upon reaching The Annex, Rone's frustration with command peeks through as he challenges the Chief's decision to keep the team idle. The Chief insists on a policy of caution: avoid confrontation and steer clear of civilians. Meanwhile, Jack meets the G.R.S. team, which includes distinct operatives like Kris "Tanto" Paronto (Pablo Schreiber), Dave "Boon" Benton (David Denman), John "Tig" Tiegen, and Mark "Oz" Geist (Max Martini), each with their own stories and skills all united by the chaos surrounding them.
In a subsequent low-key mission involving two undercover CIA agents, Sona Jillani (Alexia Barlier) and Brit Vayner, Rone's keen instincts alert him to two suspicious figures lurking close by, putting everyone in jeopardy. Jack swiftly reacts to the potential threat, warning Sona and Brit of their precarious situation.
Later, they are taken to a Special Mission compound where they meet Ambassador J. Christopher Stevens (Matt Letscher), whose seasoned diplomatic veneer is tinged with evident unease. As they familiarize themselves with the compound, additional guards such as Dave Ubben and Scott Wickland (David Giuntoli) join the growing cohort.
As the fateful day of September 11th, 2012, arrives, Stevens senses something amiss in the atmosphere surrounding the compound. Back at The Annex, the operatives make heartfelt phone calls to their families. Jack shares a tender moment with his wife Becky (Wrenn Schmidt) and daughters, but the bittersweet news about another child on the way reminds him of the personal stakes at play amidst the unfolding horror.
As night falls, a ruthless onslaught by militants commences, overwhelming the guards and inundating the compound with gunfire. Anticipating disaster, Wickland rushes Stevens and Sean Smith (Christopher Dungli) into a secure panic room. Nevertheless, the assassins pour diesel fuel across the room floor, threatening to engulf them in flames. While Wickland manages to escape, tragedy befalls, as Stevens and Smith meet a fiery end. Despite recognizing the ongoing assault, The Annex’s leadership hesitates to leverage a response, weighed down by the fear of leaving their own base vulnerable. Defying orders, the team rallies together to assist the besieged compound.
Upon their arrival, Jack and Rone discover Smith's lifeless body, a poignant reminder of the night's harrowing reality. As they grieve the loss of their comrade, the team faces an unrelenting militant assault that comes equipped with RPGs and AK-47s. In spite of the chaos, they retaliate fiercely.
As the siege escalates, the CIA agents race to establish lines of communication with nearby airbases to secure backup against their relentless attackers. They successfully reach out to Glen "Bub" Doherty (Toby Stephens), a veteran G.R.S. operative in Tripoli, who assembles his own unit, racing towards Benghazi to bolster their defense.
The Annex's defenders endure unyielding fire, but as the militants regroup and mount mortar attacks, calamity strikes — Rone falls victim to an explosive barrage, followed swiftly by Glen’s tragic demise. Oz sustains a grievous injury, leaving him with a mangled arm. Amid the chaos, Jack is confronted with Rone's death, and in an emotional farewell, he openly grieves the loss of his dearest friend.
As dawn illuminates the wreckage, the surviving team members find themselves vulnerable, yet a convoy of vehicles approaches The Annex, a glimmer of hope amid the despair. The Libyan soldiers approach, hands extended in offers of assistance, symbolizing a shift from terror to solidarity. Tears of relief pool in Tanto's eyes as Libyan personnel assist in retrieving the remains of their fallen comrades — Stevens, Smith, Rone, and Glen. The heaviness of their absence weighs starkly upon them, the gravity of their sacrifice settling in.
As the Chief prepares to leave, Jack urgently requests a private moment, loaded with emotion. “You’re not leaving until you’re on that plane,” he insists, understanding that the decisions made had dire repercussions. Before departing, Jack makes sure to tell Becky he survived, but the searing pain of Rone's loss intertwines their joyous moment, igniting a raw emotional release.
As their aircraft ascends into the sky, Jack's thoughts linger on Rone’s lifeless body, a haunting reminder of the harrowing sacrifices made. The journey home mixes relief with sorrow, thankful for the lives saved but pained by those lost.
In the aftermath, Libya faces upheaval, teetering on a precipice of chaos as extremist groups gain power. Ten days later, a massive gathering mourns Ambassador Stevens, their grief resonating through the air, a somber reflection of the attack's aftermath. In a private ceremony, medals for bravery are awarded to Jack and the surviving members of G.R.S., an honor underscored by the painful memories it evokes as they transition back into civilian life to reunite with their families.
The film closes with a poignant image, a tribute at the CIA HQ commemorating Rone and Glen — two stars engraved on the wall, forever honoring their ultimate sacrifice made in the course of duty.
