Five years after first contact with aliens, Jon Harper leads a group of civilian survivors who are low on supplies. A disbanded military squad engages in battle with an infected group of humans known as Infiltrators.
After losing a soldier, Davis decides to search for a rumored military camp called Sanctuary. Jon's group battles Infiltrators while looking for military help and supplies. Chad is injured in battle.
Darcy notices Jon's worsening condition, and decides it's best they move on and seek medical supplies. After discovering an abandoned church and reconvening with Paige and Dustin, Jon discovers that he's becoming an Infiltrator.
The other survivors no longer trust Jon, now a shadow of his old self. A serious confrontation confirms their worries. In a fit of rage, Jon leaves the church and other survivors behind.
Paige and Darcy struggle to reach Jon, who's barely hanging on to his old self. After receiving a signal from what appears to be the nearby Sanctuary, Darcy decides to trust Jon with the hope that his illness can be reversed.
Jon, Darcy and Paige find themselves under a massive military and alien aircraft battle. While searching for cover, the Infiltrator in Jon begins taking over, his demeanor switching back and forth. He realizes that he can no longer trust himself, and that he can't continue on with Darcy and Paige. The rumors of Sanctuary are confirmed as Patrollers find Darcy and Paige, leading them away.
