SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!
Outside the Wire Plot Summary
In 2036AD, a civil war between pro-Russian insurgents and local resistances in Ukraine leads the US to deploy peacekeeping forces. During an operation, a team of United States Marines and “Gumps” (robotic soldiers) are ambushed. Disobeying an order, drone pilot 1st Lt. Harp deploys a hellfire missile in a drone strike against a suspected enemy launcher, killing 2 Marines but saving 38. As punishment, Harp is sent to Camp Nathaniel, the US base of operations in Ukraine where he is assigned to Captain Leo, a highly advanced and experimental android super-soldier masquerading as a human officer.
Harp and Leo set out on a mission to prevent terrorist Victor Koval from gaining control of a network of Cold War-era nuclear missile silos, under the cover of delivering vaccines to a refugee camp. On the way, they respond to a reported attack on a friendly aid truck, resulting in a stand-off between the Marines and armed locals. After a Gump shoots a local who threw a rock at the Gump, Captain Leo negotiates a peaceful solution by giving the locals the contents of the aid truck. However, pro-Russian insurgents ambush the locals and Marines, leading to a firefight. This forces Leo and Harp to travel to the refugee camp on foot, while the Marines remain behind to engage the insurgents.
After arriving at the refugee compound, Leo and Harp are shot at by an insurgent, who kills some civilians. Leo tortures the insurgent for information, before leaving him to be killed by the gathered mob. Leo and Harp meet their contact Sofiya, a resistance leader. Sofiya leads them to an arms dealer who knows the location of a bank vault containing nuclear launch codes that Koval is looking for. Harp and Leo travel to the bank, and are met by Koval’s forces which include Gumps. While Harp helps rescue civilians caught in a crossfire between US and Russian Gumps, Leo retrieves the codes but cannot find Koval. A drone strike called in by Harp destroys the bank and several buildings, leading the military command to believe both Koval dead and Leo destroyed.
Harp reunites with Leo who tells him that he has his own plans for the codes, and has been manipulating Harp into helping him evade the eye of military command. He knocks out Harp and leaves him on the side of the road where he is picked up by Sofiya’s men. Leo meets with Koval to give him the codes but kills him when Koval refuses to give Leo access to a nuclear missile silo. Harp informs Sofiya and his commander of Leo’s actions, and they realize Leo is planning to launch the nuclear missiles in the United States, in order to prevent them from fighting more wars in the future. Harp volunteers to infiltrate the silo and finds Leo has taken over. He disables Leo but not before Leo initiates the launch of a missile, explaining that his goal was for the android super-soldier program to end in failure. Harp escapes as the silo is destroyed by a drone strike before the missile can launch; destroying Leo.
Harp returns to Camp Nathaniel and receives praise from his commander, who informs him he is going home. Harp then leaves the base.
Source: Wikipedia (CC BY-SA 3.0).