In 2011, a group of soldiers and a journalist team head out to the jungles of Belize. The mission was thought to just be plant surveillance on hostile state borders. The soldiers and Julie Evans team locate an abandoned boat in the middle of an open field. One of the soldiers advises Julie that the nearest ocean to where they found the boat is at least 150 miles. A camera with an intact SD card was retrieved from the boat. Footage from the SD card contained underwater footage and ended with a man screaming as the screen fades to black.
Afterwards, the team decides to make camp and set up security cameras. Night vision cameras show various animals roaming around. One of the cameras suddenly blacks out. At dawn, the soldiers find markings on trees near Julie's sleeping area. They soon discover that a camera - the one that blacked out earlier, was destroyed.
The group soon receives new orders from base. An archaeological team has gone missing. And they are to head to the area where Dr. Holden's archaeological team was last seen. They soon run into a man cutting wood and asks him about the missing archaeological team. He claims to have no idea where they are.
The group arrives at Dr. Holden's camp site. They only find a man who claims to also be looking for Dr. Holden. A video diary belonging to Dr. Holden is then shown. It's shown in the video that Dr. Holden located a mysterious skull inside the cave. Afterwards, a strange sound is heard and the camera woman Susan runs outside the cave panicking.
Julie is then informed that one of the two missing archaeologist has been found and they head to the location. On their way they encounter a Mennonite community. The Mennonites then proceed to show them to where Susan is. Susan claims she knows where Holden is and will take them to where she last saw him. Susan explains that what attacked them was not human. It is then that they experience a strange trembling and Susan claims that it is the same thing that happened to them.
The group runs and the camera captures what seems to be an alien spacecraft. They enter the spacecraft and Susan guides them inside to look for Holden. While looking for Holden, Susan activates a security alarm by grabbing an artifact that was on display. The group makes another escape and an explosion occurs where the spacecraft was located.
The cave where the archaeologists found the skull is found by the group. They soon enter and explore the cave. Soon, they are attacked. It is then that they locate Holden. Moving further into the jungle, the group receives more attacks from an unseen enemy. Enemy attacks continue until the following morning. Everyone is killed one by one and a last shot shows an unknown entity killing the last soldier.
An epilogue is shown where Susan claims that the skull they found shows that it's 70% human. That the alien is human kind's ancestor. Dr. Holden and Julie Evans are both officially listed as "Missing In Action