The engagement was triggered when the survivalist militia attempted to secure the satellite containing classified data which crashlanded in the mountains of Paradise Ridge in northwestern Montana, which was territory that belonged to the FIST. Unbeknownst to them, this information was sought after by the "FBI"-posing NSA operatives. These agents, under the behest of Commander Silvers, who was in turn following Mara Aramov's orders, were determined to recover the data whatever the cost, in the process attempting to terminate with extreme prejudice any witnesses. As such, their goal was to, employing total impunity, silence and neutralise the entire militia group. The defenders gathered their strength, retaliating tooth and claw to hinder the opposition, which caused innumerable casualties in both factions. Eventually the ATF became involved in the fray, with agent Teresa Lipan endeavouring to rescue the Oaktons after learning about the NSA's agenda.
The implications of the conflict were far-reaching: not only did Teresa Lipan succeed in rescuing most of the Oakton family, but she also recovered the data and escaped with the help of Gabe Logan. Consequently, she then revealed the fanatical ambition of Vince Hadden to become President of the United States of America, or at least become a government official that would possess some sort of control over the country, a plan promptly thwarted by Mara Aramov, who assassinated him when it became plain his attempt to arrest Gabe, Lian, Teresa and Mujari was rendered useless at the arrival of military police intending to capture Hadden. This resulted in the attempted apprehension of Aramov.
"Now can you tell me why it is, Mr Logan, that every agent, every witness, who can colloborate your testimony is either dead or missing?"
"I'm telling you the truth."
"I have a different version of the truth for you. There is no conspiracy, no arms consortium, only a traitor. Acting alone or with his friends."
"No! You're wrong."
"You let Rhoemer escape in Costa Rica because he was working for you. You killed Benton, Stevens, Jason Chance and Teresa Lipan because they stood in your way. You, Mr Logan, are guilty of treason! Terrorism! And murder!"
"No! You're wrong. Gabe is telling the truth!"
"I don't understand. My records seem to indicate... Coroner's report state-"
"Teresa was injured. Not killed."
"We knew that whoever was behind the Agency would be watching us closely. I faked my death so that I could investigate without interference."
"I see. Forgive me if I seem somewhat... surprised. Very well. You will understand if I wish to hear what Ms Lipan has to say... in private."
"Now... before we get to your... extraordinary resurrection, I'd like to get some background information."
"How did you become involved with the Agency?"
"Well, I joined the ATF right out of college. My first mission came when the FBI discovered a survivalist compound in Northern Montana... and I was given the task of advanced recon. I hadn't been in the ATF long, and I was still pretty green. But I knew the area surrounding the compound was put on point."
During an attempt to implicate Gabe and his team in a Senate court, the hearing between Gabriel Logan and Vince Hadden intensifies. Hadden claims that Logan is a traitor and a terrorist (believing that he let the terrorist Erich Rhoemer escape in Costa Rica because he was working for him), and accuses him of murdering Edward Benton, Lyle Stevens, Jason Chance and Teresa Lipan, his reason being that "they all stood in Logan's way". However, Teresa Lipan shows up in the testimony, revealing that she was in fact alive and was merely injured by Chance, causing Hadden to evince a measure of surprise (he admits he was "somewhat surprised"). Teresa then states she faked her death so she could investigate the actions of whoever was behind the Agency. Hadden then summons Teresa to testify in private, with which Gabe complies. Before they discuss Teresa's investigations, Hadden wanted Teresa's background information by asking her how she got involved with the Agency. Teresa replies that she first joined the ATF right after college. The FBI discovered a survivalist militia compound and a satellite impact site near Paradise Ridge in northwestern Montana and the ATF tasked her to scout and recon the area since she knew the area pretty well due to the fact she used to spend summers there with her family. This was Teresa's first and only mission while working for the ATF.
Once there, Teresa Lipan ran into two apparent FBI agents who were under fire by survivalist militias. After Teresa assists them in eliminating the militias, the agents went their own way. Later, the ATF command reports that agent DeMarco was missing and was last seen around Dead Man's Gully. Teresa offers to find him since the gully was just ahead of where she was. There she found DeMarco but was ambushed by several militia members. Once she eliminated the militia, she freed DeMarco and told him to get out of there. Up ahead, she then encountered two militia (Randy and Billy) who were under custody of two "FBI" agents. The militia tells Teresa that these agents were not FBI and there was a conspiracy going on and asks her to help them because they didn't do anything wrong. One of the FBI agents tells the militia to be silent and keep moving. Teresa then asks the agents where the power lines are to which the agent responds that they are over the next ridge. An armed militia then assassinates one of the agents and tries to kill the other agent and Teresa in an attempt to free the militias but is murdered. The agent then claims that the militia will pay for this (the death of his fellow agent). Teresa asks the agent what he was going to do, to which he suggested that she leaves now and that this is her only warning. Shortly after, she witnesses the agent murdering the two militias in cold blood, causing Teresa to be more suspicious of these agents.
Over the next ridge, Teresa planted homing beacons and reports this to the ATF command, asking them to send a strike team to the militia compound. She was then ambushed by a group of militia hitmen and promptly eliminated them. She then went her way to the crash site nearby and was shocked to discover what she sees. While she sneaks into the area, Earl Oakton was under custody of two "FBI" agents, one of whom threatens Oakton and his family with death if he does not tell him where he hid the downed satellite. Oakton does not comply and when Teresa yells at them to stop, the agent then murders him in cold blood. Another agent tells Teresa to go to where the other two agents are and then asks them what they should do with her, to which he ordered that they kill her since she has seen too much, much to Teresa's shock and horror. When Teresa got on her knees, the agent then suddenly killed the other two agents, saving Teresa's life and revealing that he was a spy. Teresa then asks what is going on and asks him who he is. The rogue agent, revealed to be Gabriel Logan, then tells her that these men are actually NSA and not FBI. He also tells her these NSA agents, led by Commander Silvers, were here to retrieve the data from the downed satellite which Earl Oakton possessed. To this end, the NSA must "neutralize" Oakton's family and his entire group of militias. Teresa questions this, claiming that "this is insane" and asks Gabe what he's going to do with Oakton's family and his followers. Gabe states that they are not part of his mission, that the data and Silvers are his top priority and that Teresa has to get out of there immediately. Teresa objects and decides to help Gabe. She also tells him that Oakton's family is innocent and that she will also help them get them out of there safely. Gabe agrees and gives her a device to help him know where she is.
After this event, Teresa goes back to the powerlines to remove the homing beacon and proceeds to head to the militia compound, along the way killing the now-hostile NSA agents. She also tries to avoid confrontation with the survivalist militia. In the closing cutscene, Teresa tells Hadden that the NSA agents made up lies so that they can go in the militia compound and kill everyone there with impunity. She waited until dark before heading into the compound.
Once inside the militia compound, Teresa Lipan is contacted by ATF Special Agent Kelly who tells her that he was captured by the survivalist militia and requests her assistance. Teresa assures him that she’ll find and rescue him. The fight between militia members and NSA agents continues, with Teresa saving as much militia members as she could while eliminating the NSA agents. She runs into a scene where Floyd, a militia member, is being interrogated by two NSA agents. The NSA agents beat Floyd to try to get him to answer where the satellite data is. Teresa then assassinates the NSA agents to save Floyd. Teresa tells Floyd that Earl Oakton is dead and that she’s come to rescue the Oakton family who are now in danger, and asks him where they are. Floyd responds that he believes Dusty Oakton (Earl Oakton’s son) took his family into the bunkers and shows Teresa how to get there by going into a nearby duct that leads to the warehouse. Floyd tells her that she should find her way from there.
While in the duct just under the warehouse, Teresa sees and overhears NSA Lieutenant Brown reporting to Commander Silvers, telling the commander that the warehouse is secure and that although there are no signs of the satellite data being there, there is a lot in there to search through. Silvers orders Lt. Brown to hold that area and tells him that he’s on his way there. Teresa assassinates Lt. Brown shortly after. After getting out of the ducts and just outside the warehouse, Teresa witnesses two NSA agents interrogating two militia members about the location of the satellite data. One of the militia members tells them that Floyd probably has it. Teresa assassinates the NSA agents before they could kill the militias who thank Teresa for saving their lives. She then asks them where the satellite data is. The militia tells her that Floyd said he hid data in a deer head and asks her to get that data out of here since it’s causing so much trouble and conspiracy. The other militia also tells her that they found and captured an ATF agent who was “snooping around the camp.” Teresa tells them that the ATF agent is Special Agent Kelly and asks them where he is. They tell her that they put Kelly under the stairs (of the warehouse) near the well right before they themselves were captured by the NSA agents. Teresa then tells the militia to get out of there while they still can.
Once inside the warehouse, Teresa overhears a discussion between Silvers and NSA agent Guzman. Silvers asks Guzman what happened there to which Guzman replies that Lt. Brown was dead when he arrived the area. Silvers believes that there is a rogue agent in the compound and orders to kill those who they deem unfamiliar. Silvers then asks Guzman if he has located the satellite data with Guzman responding that it’s not in the warehouse and the data might be somewhere in the south compound. One of Silvers’s lieutenants is in the south compound and orders Guzman to rendezvous with the lieutenant to find the data and send two more NSA agents in the warehouse for backup. Silvers also tells Guzman that he will stay in the warehouse to keep the area secure. Teresa then reports to Gabriel Logan that she found Silvers and asks him what she should do. Gabe tells her to plant the homing beacon he gave her earlier and plant it on Silvers without his knowledge by using stealth. While Silvers is distracted by hearing several reports from his agents, Teresa successfully plants the homing beacon on Silvers. After getting the report that the Oaktons are heading into the bunkers, Silvers orders his agents to get the bunker surrounded and then proceeds to go into the bunker area. Teresa reports the successful operation to Gabe who says that he is getting a strong signal from Silvers and then tells her to get out of there immediately. Teresa tells him that she’s not done yet and she has to rescue the Oaktons first.
Later, Teresa finds ATF Special Agent Kelly and unties him. He also obtains a .45 handgun. Several NSA hitmen appear but they were all eliminated by both Teresa and Kelly. Kelly then tells Teresa that they should get out of there but Teresa tells him that she has to rescue the Oaktons first and asks him not to get involved in this. Kelly obliges and leaves the compound. Teresa proceeds to go into the well where it leads into a cave where she sees two militia members discussing how they should get out of the compound. With no way out, one of the militia suggests they should stay there and wait for help. Teresa then shows up to where they are and the militia orders Teresa to stop and kneel down where she is if she wants to live. The militia asks her who she is and (being a federal agent) why she’s there to kill them all. Teresa assures them both that she’s not there to kill them (and the other militias) and that she just wants to get the Oaktons out of there alive. Since Teresa has proven herself to be an ally by saving several militias, the militias agree to help her fight the NSA agents so they could give them “three targets instead of one.” They then proceed to go out of the cave and into the south compound where several more militia members and NSA agents are battling. They eliminated many NSA agents along the way. Teresa then heads into a house-like building and obtains the satellite data hidden in a deer head, as the militia member earlier points out. Nearby, Teresa assists the militias by eliminating three NSA snipers in the bunker building area. Once inside the bunker building complex, Teresa and the militia then proceed to eliminate three more NSA agents, who seem to have no idea where the bunker entrance is. Teresa asks the militia where the Oaktons are, to which the militia replies that Dusty Oakton took his mother, Debbie Oakton, into the bunker and pulled the dirty mattress over the entrance to hide their escape. Teresa pulls the mattress away and goes into the bunker entrance.
When Teresa Lipan reaches the bunker, she is met by a suspicious Dusty Oakton who demands to know who she is and his father’s whereabouts. Teresa replies that his father sent her to rescue him and his mother, Debbie Oakton, in order to gain his trust. Dusty then mentions that his mother is in labor to which Teresa requests to take her where she is and assures him that she will get them out of there. Dusty then leads the way towards Debbie’s location with Teresa protecting him along the way from the NSA agents, who have managed to break into the bunker. Dusty also sets up explosives to slow the NSA agents down. He also trusts Teresa enough to allow her to get some supplies and weapons in the bunker. He also gives her infrared goggles to go through the darker paths of the bunker.
When they reach their destination, Debbie asks his son who Teresa is and where his father is. Dusty replies that Teresa is there to rescue them and that she can trust her, even going as far as calling her a friend. Teresa informs Debbie that they need to get out of there immediately because the NSA have managed to break into the bunkers and the security doors won’t hold them out for much longer. Because Debbie is in preterm labor (barely 30 weeks) and thus immobile, she asks Teresa to go into the food cooler room to get the first aid kit containing terbutaline so that she can administer it to Debbie, which will delay her labor and allow her to move. While Teresa goes to find the first aid kit, Dusty stays with Debbie to watch over her.
After finding the first aid kit and going back into Debbie’s room, Teresa manages to kill a few NSA agents who are attempting to kill all three of them. Dusty also manages to arm himself with an M-16, which he obtained from a supply closet. Teresa then gives the terbutaline shot to Debbie, allowing her to move albeit at a very slow pace. Teresa then escorts Debbie while protecting her from the NSA agents. Meanwhile, Dusty goes to the computers to back up data files. After backing up the files, Dusty destroys the computers and proceeds to help Teresa escort Debbie to the main room. When they reach the room, Dusty sets off some explosives in the entrance to slow the NSA agents down “for good”. Dusty then opens the secret passage (behind a US flag) so that they can go in and escape the bunker through the ladder. Before joining them, Teresa kills a few more NSA agents who have managed to get in the room through openings in the ceiling. Teresa then contacts Gabriel Logan to pick them up.
With Vince Hadden now rendered useless after his attempt to convict Gabe Logan and his 'accomplices' fails, Mara Aramov appears on Mihai Niculescu's orders, killing the Secretary of State. She tries to release a few bombs in the general vicinity, while Gabe Logan races to stop her, resulting in her attempted apprehension.