Clarke and Finn attempt to broker peace with the Grounders while others prepare for battle. Meanwhile, tragedy strikes the Unity Day celebration.

John Murphy returns claiming to have been held captive by the Grounders and Clarke and Bellamy have different ideas on how to handle his return.

Clarke and Finn lead a hunt for food, Raven makes Bellamy an offer he can’t refuse, and Kane risks his life and reunites with Jaha and Abby.

Clarke and Finn are confronted by a new enemy, Bellamy makes a heroic move to save Jasper, while those on the Ark face the inevitable.

As the conflict escalates, Clarke pleads with Bellamy to do the right thing. Octavia makes a difficult choice. Raven and Jasper work against time.

Trapped in the white room, Clarke tries to make sense of her surroundings. The Ark survivors face moral and physical dilemmas. An old enemy returns.

A suspicious Clarke confronts President Dante Wallace and demands answers. Kane interrogates one of the 100, and Abby performs emergency surgery.