Fifteen years after all the world's electricity mysteriously shuts down, Charlie Matheson seeks help from her estranged uncle to rescue her brother from a ruthless warlord.
Miles takes Charlies and the others in search of an old friend he thinks can help them rescue Danny, but find her a prisoner on a chain gang. Danny witnesses Captain Neville's brutality firsthand.
Miles and Charlie arrive at the rebel's camp only to learn that their position may be compromised. Maggie and Aaron make a discovery at Grace's house, and Danny stands up to his captors.
The reunited group is attacked by dogs, and Maggie recalls her past after the blackout. Miles resolves to leave the group, and Danny and Captain Neville are thrown together in the middle of a storm.
The group closes in on Danny and discover a working train, which Miles believes Captain Neville will use to transport his prisoner to Philadelphia. While Neville recalls his life before the blackout, Nora hatches a plan of her own.
Short on options, Miles takes the group to an old acquaintance who can save Nora's life -- but the man demands that Charlie kill for him before he will let them go. Aaron remembers his life just after the blackout, and Danny arrives at Monroe's capitol.
The group stumbles upon Nora's sister, who is being held captive by a ruthless militia leader in order to blackmail her. Captain Neville learns that his own son may not be safe in Monroe's hands.
Charlie must infiltrate a brutal training facility when she pledges to rescue an orphan boy taken by the militia. Rachel is reminded of her past and her husband's secret project -- which is connected to the blackout.
With help from the Resistance the group moves through a tunnel to infiltrate Monroe's headquarters in Philadelphia, but begins to suffer the effects of oxygen deprivation. Meanwhile, Monroe grows suspicious of Rachel's activities.
When the group arrives in Philadelphia, Miles faces the reality that he may have to confront Monroe himself. Rachel is forced to continue her work for the enemy, and Charlie comes face-to-face with the mother she thought was dead.
Rachel and Miles go in search of a man who can even the odds with Monroe's newly-empowered forces, while Charlie and the others bring a warning to the rebel headquarters.
Miles offers to join the rebels, and goes in search of a former militia comrade to help the cause. Meanwhile, Randall Flynn offers Monroe a way to one day seize control of the entire continent, and Charlie, Aaron, and Rachel attempt to elude capture.
When Monroe sends Major Neville on a mission to test his loyalty and usefulness, the Resistance attacks his convoy and takes him prisoner. Meanwhile, Aaron tries to convince Rachel to undertake a dangerous mission to the Tower to turn the power back on.
Miles, Charlie, and Nora trek to the Georgia Federation to stop Monroe's plans, where Miles encounters a close friend still in the service of the enemy. Rachel and Aaron search for an ally but encounter trouble on the road.
As Miles takes up his new role as a General, Monroe uses loved ones from his home town in a plot to trap his old friend. Aaron and Rachel cross into the Plains Nation, where Aaron is shocked to encounter someone from his past.
When the Georgia President assigns Miles and Tom Neville to work together, they must hunt down a scientist who is creating weaponized anthrax for the enemy. Meanwhile, Aaron and Rachel run into more trouble on the road.
When a devastating drone attack leaves the rebels in disarray, Miles leads a mission to find Charlie and Jason. Meanwhile, Aaron tries to reprogram a nanotech device in an attempt to heal Rachel's injuries, and Monroe grows suspicious of someone close to him.
Nora finds herself a prisoner of Monroe, who takes his forces after Rachel when he discovers the potential power waiting for him inside the Tower. Miles and company are waylaid in their attempt to reach Rachel first -- while Rachel herself sets her eyes on Monroe.
Monroe and his men gain access to the Tower, only to find that they are not alone there. Meanwhile Miles meets up with Aaron and also enters the structure, and Tom tries to incite a new rebellion against his former commander.
Rachel leads a team to the forbidden Level 12 to turn the power back on, while Monroe faces a mutiny from his own soldiers. Miles remembers the events that led to his separation from Monroe, and makes a fateful decision about the man he once called friend.
