Rachel releases the pin in her grenade, standing inside of Monroe's tent. In a matter of seconds, Monroe's guards spring into action to protect their leader. One of them wrestles the grenade from Rachel and tosses it outside just in time. Moments later, Aaron sees Rachel in chains; his chance to get into The Tower is gone. Monroe places Rachel's hand on the palm reader and the door opens. Inside, Rachel and Randall discuss how she got in; he's the one with security clearance, not her. Randall assumes Grace "got loose," and he's going to get to the bottom of it. Outside, The Tower doors suddenly swing shut, locking Monroe's men out. A group of mysterious people led by a man named Jenkins watch the proceedings over surveillance monitors, then shoulder their weapons and head out with a plan to introduce themselves to the interlopers.
Miles and his crew land their helicopter four miles south of The Tower. On their hike to the base of the complex, they run into Aaron; after an initial period of shock and disbelief, Aaron says he can get them into The Tower, but only if they can find a way around Monroe's troops. Inside The Tower, Randall shows Monroe the control room, where the U.S. government's satellites still have live feeds of the entire planet. The Tower has the capacity to do anything and is impervious to everything, but they'll have to get to Level 12 first. Rachel is shocked when Randall reveals this, but Monroe marches his troops to the elevator, ready to witness the entirety of The Tower's potential.
Monroe and his group take the elevator to Level 12, but it stops on 11. Something's wrong. Monroe's men step out to figure out what's going on as klaxon starts blaring. Suddenly, Jenkins' men begin firing on the group! Monroe's men fall one by one as Rachel runs for cover in a reinforced room. Monroe follows behind her, and when she tries to stab him with a knife, he wrestles it away from her and demands to know who just attacked them. Outside, the Nevilles take out the Militia encampment's power source. Aaron and Miles rush to open The Tower doors, as Monroe's men descend. Aaron gets them inside just in time, forcing Miles to make the tough call to close the door before Jason or Neville can get in.
Inside their bunker, Monroe tries to conjure up an escape plan with Rachel; their only way out is to help each other. But why would she help him when all she wants to do is kill him and die? In his scramble, Monroe finds some massive coil guns encased in plexiglass safe and asks Rachel if she knows how to get them loose. She does, but she's not telling him how. In a flashback to the week before the Blackout, Rachel and Ben argue about the upcoming launch. She wants to talk Randall out of it, but Ben knows there's nothing they can do. Annoyed by his condescension, Rachel thinks they may need to spend some time apart. If only she knew the grim reality of that proposition...
Miles and his group walk across the massive catwalk of the Tower. They're amazed by its grandiosity, and for Aaron, it's akin to a spiritual experience. When they get to the massacre site, Miles thinks he sees Rachel amongst the fallen corpses, but it's not her. Charlie wonders who did this... and with what. A steady beeping noise catches Aaron's attention, and he realizes the elevator is descending to their position. He warns the group - someone's coming. Outside, Monroe's men have taken Neville and Jason captive; they want to know how Neville helped Miles get in. Neville uses the opportunity to play mind games about Monroe's state of mind - is he still murdering his best men? When the guards leave, Neville tells Jason they'll have to look after each other if they want to make it out of this camp alive.
Miles and his group take refuge in a lab, which is full of monkey skeletons. Suddenly, a man with a gun starts shooting the door down and they all look for an escape. In their bunker, Rachel tells Monroe this place used to be Cheney's secret VP hideout; she knows how to get the guns out of the safe, but she can't forgive Monroe for killing Danny. When Monroe tries to back away from her attack, she demands he take responsibility, and he breaks down, telling her he has a son he's never met. No more excuses for Monroe; he knows exactly how much blood is on his hands. In a flashback to four months after the Blackout, Ben attempts to connect with anyone on his computer, asking if anyone's out there. Breaking down, Rachel sobs to Ben about millions of people's blood being on their hands - how are they supposed to live with that? She doesn't know if she can... While Ben comforts his wife, a message from Grace appears on the computer screen.
Miles and his group find an escape through the ventilation tunnel. Aaron lets everyone know their enemies - whoever they are - might be using electromagnetic coil guns, which is why they do so much more damage than regular guns. Miles knows they'll need one if they hope to survive. Aaron points to an armory on his Tower schematic, and Miles decides to make a run for it. The only problem is, the armory's been sacked... there's nothing left.
Captain Riley, one of Monroe's men, checks on Neville who's tied to a post in a tent along with Jason. Neville tries to break Riley down, claiming he can see the fear in his eyes; Riley isn't committed to Monroe. Monroe's killed everyone who was ever loyal to him. What's left? Neville tells Riley they can stage a revolt and finally do something positive for the world; they can make a difference. Jason chimes in, reminding Riley that Neville was always all about the welfare of his men. Riley thinks about this for a moment, before coming to his senses and accusing both Nevilles of just trying to save themselves.
On a monitor in her bunker, Rachel sees Charlie, Miles, Aaron and Nora hiding from guards. What are they doing here? She worries about her daughter's safety, so when Monroe promises to protect Charlie, Rachel lets Monroe talk her into opening the gun safe. Moments later, Monroe saves Charlie from certain execution by shooting one of Jenkins' men. Monroe runs off as Rachel holds her furious daughter back. Charlie doesn't care that Monroe saved her life - she wants him dead. As Charlie, Rachel and Aaron move further into The Tower, they're stopped by three of Jenkins' men, all with electromagnetic guns. They're stuck.
Miles and Nora are in a firefight of their own, taking out Jenkins' men one by one. Suddenly, Monroe shows up out of nowhere and corners Miles. As he approaches his old friend with an electromagnetic gun, Monroe says he wants to settle things once and for all. Miles pops out of his cover to aim his electromagnetic gun at Monroe. Things are about to be settled, one way or another.
Rachel, Aaron and Charlie are led by gunpoint into a giant underground commune - there are hydroponic plants, beds and kitchens. It's an entire village. Out of the shadows steps Grace Beaumont. Alongside her is Dan Jenkins, the leader of the group. They mean Rachel no harm, and they know who Aaron is - he's a bit of superstar to them. The group comprises those left behind in The Tower when the power went out, and they rescued Grace. Since then, they pledged to protect the world from outsiders trying to harness The Tower's capabilities. No one's been to the 12th floor since the Blackout. It's too dangerous; that's why they dismantled the elevators and sealed themselves in. Dan can't remember the last time he saw sunlight. He lets Rachel know they spared her in the earlier chaos - and asks her not to make him regret it.
Neville and Jason are still tied up in the Militia tent when Captain Riley enters to tell Neville that guys like him could get shot just for thinking about a coup. Nevertheless, Riley has been convinced by Neville's earlier speech. He lets both men go and hands Neville a gun. If he wasn't sure about Neville's honesty a few minutes ago, time is about to reveal the truth. Riley walks out and Neville approaches his son. It's time to roll.
Dan takes Warren's journal and tosses it into a metal pan before dousing it with gasoline. Aaron makes an impassioned plea to him to turn the power back on. Jenkins knows electricity will give weapons to the evil ones in the world, but Aaron thinks its more than that: it's protection for the good people, it's clean food and water, it's a chance to make the world better. Dan lights the notebook on fire anyway, as Grace asks Rachel to tell her friends the truth about the power. Rachel remains mum, unable to verbalize it; so Grace does it for her... turning the power on could save the world - or it could set the world on fire.