In late 2007, the Iraq war is winding down: President Bush has declared victory, and rebuilding operations are in effect. Sergeant Matthews and his spotter Sergeant Isaac are sent to a pipeline construction in the middle of the Iraqi desert. All the Americans working at the site have been killed, so now it is their mission to find the culprit before they send new builders.
The soldiers hide behind a bunch of bushes and stones to watch the location under the melting sun, and twenty hours pass without anything happening. Matthew begins growing impatient and starts to think there are no Iraqi soldiers left, and considering the scattered bodies, the site must have been attacked by a team that left after completing their mission. Isaac points out there are no signs indicating a big group moving around here, and points out that because all the workers were killed by headshots, this could have been done by the legendary professional Iraqi sniper known as Juba.
However, Matthews thinks it is impossible for anyone to kill this number of people in less than thirty seconds. Eventually Matthews finally gets tired of waiting and goes down to take a closer look at the location after asking Isaac to cover for him. Isaac explains his scope is becoming unclear, and Matthews teases him for not changing it sooner, but this one is important for Isaac because it used to belong to a fallen comrade.
Then Matthews goes from body to body looking for clues and begins believing Isaac's theory when he confirms everyone died from precise headshots. He goes to the middle of the site to figure out the possible direction of the shots while Isaac begs him to retreat, but suddenly a shot is heard and Matthews falls to the ground, suffering great pain in his abdomen. Desperate to help his friend, Isaac runs down in a zigzag path to avoid any incoming bullets, but when he is about to reach Matthews, he gets shot in the leg.
Isaac has no choice but to leave Matthews behind and run to hide behind a broken wall. Suffering but still alive, Matthews contacts Isaac and tells them to call the base and ask for backup. First though, Isaac notices his leg wound is quite awful, so he proceeds to tie a belt around it to stop the bleeding.
Then he grabs his radio bag and tries to contact the base, only to discover he has no signal because the sniper had shot the antenna. Suddenly Matthews contacts him again and asks him to spot the sniper so that he can aim at him, ignoring Isaac when he warns him that the sniper will notice any movement and shoot him again. Isaac starts working on making a hole in the wall with his knife to insert the scope, only to get his hand hurt by some falling rocks.
Matthews then proceeds to attempt to reach for his rifle, only to pass out because of blood loss. Not wanting to end like his friend, Isaac uses a blade to remove the bullet from his leg, which is an extremely painful process, then he bandages the wound before passing out as well. Sometime later, Isaac wakes up when he hears a strange noise coming from his earpiece.
It turns out to be an officer from the base, and Isaac immediately begins reporting the situation and begging for medical supplies. However he begins to get suspicious when the officer asks him lots of weird questions, and most importantly, he requests him to either tell them his exact position or stand up and fire in the air, claiming it is for the helicopters to drop the supplies accurately. Isaac points out this is against protocol and will put him in danger, and when he begins paying more attention to the man's words, he realizes his accent is not American.
This is Juba the sniper, who has hacked into the radio frequencies to try to set a trap. Isaac does not fall for it and calls him out, but instead of hanging up, Juba begins asking him questions, claiming he wants to know Isaac better. Isaac tries the radio again, but it is still not working.
Juba insists on making his silly questions, and when Isaac refuses to chat back, Juba threatens with shooting Matthews again, which is risky because there is a chance he is still alive. Isaac agrees to chat for a while and asks Juba to go first while he begins drawing a map of the site on the dirt to calculate the bullet trajectory and find the possible location of the sniper. Juba tells him he is just a regular Iraqi citizen that wants to save his country and asks Isaac to tell him about his family, but Issac points out that is too personal.
Then Isaac makes fun of Juba's reasoning, saying that he is killing the people that are actually trying to develop the country by bringing schools, pipelines, and infrastructures that will boost the local economy. This makes Juba laugh, and he explains that the money made here will be sent back to the USA later. As time passes, Juba keeps asking questions, but Isaac continues to refuse to say anything personal about himself, making Juba threaten to shoot Matthews again.
However Isaac does not believe him anymore. To prove he is dangerous, Juba tells Isaac the name of the previous owner of the scope and that he is dead, quoting Matthews' earlier teasing. This means Juba has been listening to their conversations since they arrived.
Using his scope, Isaac notices one of the dead men has a radio with them and he drags his body to the edge of the wall, but not even using a piece of wood he would be able to reach it without exposing himself. Next, Isaac tries to drink some water from his bottle only to find it empty because of a hole in it, which Juba confirms he did on purpose. He also admits he did not miss any shots: he specifically shot the bottle, the antenna, and Issac's leg in order to put Isaac in an unescapable situation and make him die slowly, which he will enjoy hearing through the communicator.
When Isaac finds the bullet he took off his leg, he takes a closer look and begins calculating the weapon model Juba has by making some sneaky questions. He also calls Juba a terrorist, which makes Juba laugh again as he points out that the Americans are the ones illegally entering a foreign country with weapons ready to kill people. While Juba talks, Isaac does some more calculations and looks through his scope to finally reach the conclusion that Juba is hiding under a huge pile of trash.
He has been under these harsh conditions for a long while, not to mention the overwhelming heat, meaning this guy truly is a professional. However Juba denies being the famous sniper and once again claims to be a regular Iraqi man. Judging by his accent, Isaac guesses Juba must be a former US army officer that betrayed them, but Juba dismisses this as well and explains he only kills people that attack him first.
In return, Isaac shares the story of how he met his best friend when he was a child and how they enlisted together later as adults. Soon dehydration and exhaustion begin having a hard effect on Isaac, who falls to the ground as he hears Juba tell him he will staple his tongue to his chest. Next, Isaac tries to trick Juba by putting a jacket and helmet on his rifle and waving it above the wall, but Juba does not fall for it.
What does fall is the helmet, landing on the other side of the wall, so now Isaac can not protect his head either. Such a silly mistake is the sniping point and makes him cry. More time passes, and Isaac becomes desperate enough to try to take a risk.
He runs towards a body lying on the ground and steals his bag and radio before running back to the wall as he dodges all the bullets Juba immediately throws at him. In the bag, Isaac finds water and some candy that he immediately devours, but unfortunately this radio isn't working either. Juba also punishes him for this risk by shooting at the wall and heavily damaging his scoper.
Suddenly, Isaac hears some disturbance coming from his earpiece and realizes it is Matthews, who is still alive. Isaac yells the location of the sniper at him, and Matthews immediately takes out a piece of metal to use in order to look at the pile of garbage. While Matthews moves extremely slowly to grab his rifle, Isaac keeps the sniper distracted by making small talk, and he learns that Juba used to be a teacher in Baghdad.
When his students got killed during an American attack, he decided to get revenge. The wall Isaac is hiding behind is the ruins of said school. Then Juba asks Isaac while he keeps carrying the damaged scope, but since Isaac refuses to answer, Juba threatens to shoot Matthews again.
Desperate to save him, Isaac confesses that he keeps the scope in memory of his old friend, who died because of a mistake Isaac made, and he still feels guilty. In the meantime, Matthews places his rifle and blindly aims at the pile of trash, shooting at all the bullets he has as Isaac shoots as well to pretend the noise comes from him. When Matthews is about to reload his gun, Juba suddenly shoots him back, hitting him right on the shoulder.
Isaac asks Matthews to crawl toward him to find safety behind the wall, but unfortunately when Isaac goes close to the edge to help, Juba shoots Matthews in the head. Isaac has to watch him die and finally snaps right into a breakdown, saying he wants to go home. Juba informs Isaac that if he really wants to leave then he will not shoot him, but Isaac is skeptical.
Later, Juba asks Isaac why he is still there despite the war being already over. Isaac pauses for a moment before replying he is there because it was actually he who killed his old friend. It turns out he accidentally shot his previous sniper partner while trying to kill an enemy, and Isaac has been lying to everyone, saying his friend had been killed by the bad guys.
Suddenly Isaac hears some noise coming out of the radio and rushes to check the signal, being happy to hear conversations going on. However his happiness is short-lived because while he can hear voices, he can not send any messages because of the damage the radio took. To Isaac's shock, Juba joins the conversation he is hearing, and the man uses Isaac's name to ask for help.
Isaac finally realizes that all this time Juba has been hacking into American communications, pretending to be a soldier needing help to lure backup teams to the area and kill them all easily thanks to the surprise factor. Isaac tries to interrupt the conversation to no avail. Sometime later, Isaac wakes up to the painful feeling of a crow pecking on his leg wound.
Seeing as even the birds think he is already dead, Isaac decides to take a risk and retrieves Matthews' rifle using some rope and a stick, then he aims it at the pile of trash. At that moment, helicopters arrive at the area and reveal Isaac's location without knowing this is a trap. Wanting to save the incoming soldiers, Isaac pushes the wall to make it crumble, creating a curtain of dust that makes it hard for Juba to get Isaac's location.
Isaac begins shooting at the pile of trash without knowing if he has hit his target or not. In order to find out, Isaac finally stands up from his position, and he is shocked to notice Juba is not using this chance to shoot back. This makes Isaac believe he has effectively killed Juba.
Soon the helicopters arrive and quickly carry Isaac away on a stretcher, immediately giving him medical attention. Isaac tries to tell them about Juba, but he can not be heard because of the noise from the helicopters taking off. Suddenly Juba starts shooting at them, killing the medical soldiers one by one before hitting the pilot as well.
The helicopter quickly goes down and crashes on the ground, instantly killing Isaac and allowing Juba to keep his word: technically, Isaac had not been shot. Then Juba hacks into the USA lines again and pretends to be an American soldier to lure his next team of victims.