In a time long ago, the McCullen family was notorious for producing arms, supplying both sides during a brutal conflict. An ancestor of the McCullen clan was captured and imprisoned in France, enduring imprisonment with an iron mask to serve as a warning for future generations against repeating similar transgressions. Determined not to remain mere suppliers for wars, McCullen pledges that the McCullen lineage will now dominate warfare.
Fast forward to a technologically advanced near future, we meet weapons specialist James McCullen (Christopher Eccleston), who is the mastermind behind a revolutionary weapon known as Nanomites. These nanotech innovations are designed to consume metal and other substances, capable of wreaking havoc on anything from armored tanks to entire cities. However, there's a catch—the nanobots can only be neutralized by using a designated kill switch.
M.A.R.S., McCullen's company, provides NATO with four warheads, and American soldiers Duke (Channing Tatum) and Ripcord (Marlon Wayans) are tasked with delivering them. However, their convoy falls victim to an ambush led by the enigmatic Baroness—Duke's ex-fiance, Ana Lewis ([Sienna Miller]). Armed with advanced weapons, the Baroness and her forces quickly overpower the NATO troops, resulting in a devastating loss.
Fortunately, Duke and Ripcord are rescued by an elite team, including Scarlett ([Rachel Nichols]), a prodigy who graduated college at the age of twelve and serves as the unit's intelligence expert; Snake Eyes ([Ray Park]), a silent ninja commando; Breaker ([Said Taghmaoui]), the team's tech specialist; and Heavy Duty ([Adewale Akinnuoye-Agbaje]), an expert in ammunition and field leadership. As Ana’s forces withdraw, the team brings the warheads back to The Pit, the G.I. Joe command center located in Egypt, where they meet General Hawk ([Dennis Quaid]), the formidable leader of the G.I. Joe team. Although initially excusing Duke and Ripcord from further involvement, Hawk is persuaded to welcome them aboard when Duke mentions his acquaintance with the Baroness.
As Hawk requests McCullen to remotely unlock the weapon’s case, he inadvertently activates a tracking device, leading to the revelation that McCullen is utilizing the very same nanotechnology to construct a formidable army of super soldiers, aided by the Doctor ([Joseph Gordon-Levitt]), the Baroness's brother. With revenge at the forefront—stemming from a deep-seated grudge against the French for his ancestor's disgrace—McCullen plans to utilize the warheads to instigate global fear and establish a new world order.
Under McCullen's orders, Storm Shadow ([Byung-Hun Lee]) and the Baroness launch an operation to retrieve the warheads from the Joe base, employing innovative mole pods to infiltrate the stronghold. Though they successfully escape with the warheads, the Joes soon follow in hot pursuit to Paris, seeking to thwart McCullen's diabolical scheme. A dramatic showdown ensues as the Joes confront Ana and Storm Shadow during the missile launch, which disastrously strikes the Eiffel Tower, unleashing the destructive Nanomites throughout the city.
As chaos unfolds, Duke finds himself captured by McCullen, leading to a daring rescue mission by his comrades. With each confrontation revealing deeper connections, it becomes clear that the architect behind the sinister plot is none other than the Doctor, who harbors a vendetta against Duke following a tragic misunderstanding during a past mission. The ensuing battles showcase not only fierce physical confrontations but also a gripping emotional narrative involving Duke, Ana, and their intertwined fates.
Ultimately, the climax brings forth explosive confrontations as Duke and the Baroness fight back against the odds. With the threat of missile strikes hanging heavily in the air—notable targets being Beijing, Moscow, and Washington, D.C.—the Joes race against time to dismantle McCullen's plans. As Snake Eyes and Ripcord fight to defuse the crisis, alliances are tested, old scars are reopened, and the struggle for control escalates to epic proportions.
In the final showdown, the true power of the Nanomites comes to light, revealing the devastating depths of betrayal, loyalty, and sacrifice. As the Joes confront McCullen and his army, the fight for not just their lives, but the safety of the world may very well rest in their hands, culminating in a breathtaking battle that determines the fate of humanity.
