Finn arranges a meeting with Clarke and the leader of the Grounders in order to bring peace, however a sceptical Clarke warns Bellamy, who along with Jasper and Raven follow them to the meeting with weapons. On the Ark, Diana takes over the exodus ship.

Clarke and Finn come face to face with a new enemy after Lincoln rescues them from Anya, while Bellamy, Raven, Octavia and Jasper deal with a vengeful Murphy. On the Ark, Jaha makes a plan to try and get to Earth.

As the remaining members of the 100 face off against the Grounders, Jaha makes a noble sacrifice to ensure the Ark makes it to Earth.

Clarke is still on her own in the white room, frantically attempting to make sense of her bizarre surroundings. Lincoln and Octavia's plan is ruined and an enemy returns.

Clarke wants answers from the President. Abby performs emergency surgery. Octavia will do anything to find Lincoln.

After discovering a horrifying project in Mount Weather's medical ward, Clarke joins forces with an unexpected ally.

Clarke ends up being betrayed by somebody that she trusted. Bellamy, Finn and Murphy attempt to save a stranger.