After leaving Camp Arkadia due to her inability to accept her actions, Clarke sets out on her own, dealing with her emotions while encountering new challenges. Camp Arkadia begins to see political turmoil as the hunger for power mounts.

Bellamy and Kane put their lives on the line to rescue Clarke. Abby considers opening Mount Weather as a medical facility. Murphy schemes against Jaha.

Now with Clarke in her possession, Lexa has the power to force Skikru to become one with the grounders. Kane and Abby journey to the Polis Summit, while the Ice Nation prepares to draw first blood against Skikru and the other grounder clans.

Clarke discovers the mastermind behind a devious plan, while Kane struggles to keep the peace. Meanwhile, Jasper's grief drives him to reckless behavior.

Pike's twisted crusade threatens Clarke's attempts for peace. Raven becomes a target, while Murphy tries to conspire against Jaha.

Clarke struggles with her morality while Abby grows suspicious of Jaha's motives.

Anger and lust for vengeance and justice from the clans threatens Lexa's position. Murphy unveils new secrets about the identity of Polis. Meanwhile, a dangerous coup brews against Clarke and Lexa and their trust for each other is tested.

Kane tries to stop Pike, but he learns that he is onto him. Kane realizes that for him to ensure peace in Arkadia, he'll have to go through drastic measures.

Bellamy tries to save Kane from Pike. Clarke and Murphy debate over what to do with Titus and the A.I. Bellamy confronts Octavia.

Jaha employs a terrifying new method to convince Abby to join his cause, Kane is on a mission, and Bellamy is hit with a hard truth. Meanwhile, Monty finds himself in a precarious situation, and Jasper rushes to save one of his own.

Clarke and her friends try to save Raven from Alie's control. However, they realize that they will have to undergo dangerous procedures that may cost Raven's life.

Jaha returns to Polis, and Murphy has a surprise encounter. Meanwhile, Octavia uncovers a clue.

Clarke is on a mission that could change everything. Meanwhile Murphy gains insight that might prove useful in ensuring his survival. Lastly Kane reaches a breaking point.

Clarke, Bellamy, Octavia and Jasper hit a tragic roadblock. Meanwhile, Raven and Monty make an important discovery.

Clarke finds hope in a place she never expected. Alie's master plan begins to coalesce.

In the second half of the two-part season finale, everyone prepares for a final showdown as they begin to face the reality of their tragic situation in the epic and mind-bending conclusion.