One hundred young exiles from a dying space station are sent to Earth 97 years after a nuclear apocalypse to test if the planet is now inhabitable.
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.
Having discovered that Jasper may still be alive, Clarke, Bellamy, Octavia, Finn and Monty set out on a mission to locate their friend.
As the conflict escalates, Clarke pleads with Bellamy to do the right thing. Octavia makes a difficult choice. Raven and Jasper work against time.
In The 100 S01E03, A fast-moving, toxic fog jeopardizes a mission to find a substance that could save Jasper’s life. Clarke learns the truth about her father’s betrayal.
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.
After a shocking death, Clarke and Finn grow closer. Bellamy must keep the group from turning on one another and Abby takes a huge risk.