Set 97 years after a nuclear war has destroyed civilization, when a spaceship housing humanity's lone survivors sends 100 juvenile delinquents back to Earth in hopes of possibly re-populating the planet.
Eliza Taylor / Bob Morley / Paige Turco / Marie Avgeropoulos / Devon Bostick / Christopher Larkin / Isaiah Washington / Henry Ian Cusick / Lindsey Morgan / Ricky Whittle / Thomas McDonell / Richard Harmon / Sachin Sahel / Jarod Joseph
It's a race against the end of the world as Praimfaya arrives forcing our heroes to make impossible decisions to ensure their survival.
Jaha and Kane disagree over how to handle their grim reality. Meanwhile, Clarke leads a group to save a friend.
Clarke faces the consequences of her fateful choice.
Octavia fights in the final battle for survival, but not everyone is willing to play fair.
Clarke struggles to keep the peace after word of Jaha's discovery spreads.
Clarke and Abby question how far they're willing to go when they make a disappointing discovery; Jaha finds a lead to the Second Dawn.
Clarke's arrival on the island quickly takes a turn for the worse. Meanwhile, Bellamy tries to avoid further tragedy in Arkadia.
Clarke and Roan are forced to work together when they are tasked to deliver a dangerous but crucial asset to Abby through enemy territories.
Clarke pleads with a former allied force to avoid a war and ensure her people's survival.
Clarke's decision on who gets to live causes tension in Arcadia. Jasper loses his sanity when the Black Rain falls. Bellamy and his friends face judgement for their crimes against the Ice Nation.
The burden of leading weighs heavily upon Bellamy (Bob Morley) and Clarke (Eliza Taylor) when different challenges force them to determine who will live and die.
Show creator Jason Rothenberg and cast members discuss the season three finale, what fans can expect in season four and answer fan questions.
Clarke finds hope in a place she never expected. Alie's master plan begins to coalesce.
Clarke, Bellamy, Octavia and Jasper hit a tragic roadblock. Meanwhile, Raven and Monty make an important discovery.
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.
Alie forces Raven's dark side to come out, Jasper's anger continues to grow. Meanwhile Octavia wrestles with her place in the world and Monty is forced to make a split second decision.
Clarke and her friends try to save Raven from Allie's control. However, they realize that they will have to undergo dangerous procedures that may cost Raven's life.
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.
Bellamy tries to save Kane from Pike. Clarke and Murphy debate over what to do with Titus and the A.I. Bellamy confronts Octavia.
Clarke struggles with her grief and rage. 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.
Anger and lust for vengeance from the clans threatens Lexa's position. Pike learns that there is a traitor in his midst. Meanwhile, a dangerous cou brews against Clarke and Lexa.
Clarke struggles with her morality while Abby grows suspicious of Jaha's motives.
Pike's twisted crusade threatens Clarke's attempts for peace. Raven becomes a target, while Murphy tries to conspire against Jaha.
After leaving Camp Jaha due to her inability to accept her actions, Clarke sets out on her own, dealing with her emotions while encountering many new challenges. Camp Jaha begins to see political turmoil as the hunger for power mounts.
Clarke gets help from a source she did not expect; Cage continues on his mission; Bellamy and the group continue their efforts to break free.
Wick and Raven are faced with a setback; Maya and Jasper witness a terrible act.
Lexa and Clarke get into a heated discussion during battle preparations; Bellamy races against time.
Clarke begins to question Lexa's leadership decisions and Indra continues to push Octavia. Meanwhile, at Mount Weather, Jasper steps up into the role of leader, and Cage throws Maya into a life threatening situation.
Clarke is faced with a difficult choice and Raven helps Bellamy navigate Mount Weather as Dr. Tsing begins to harvest the 47, while Jaha and Murphy encounter a stranger on their journey to the City of Light.
Bellamy receives help from an unlikely source after being captured. Meanwhile, Abby fights to stay in control, and Jasper confronts President Wallace.
Clarke and Lexa encounter a new enemy. Bellamy and Lincoln work together to break into Mount Weather. Murphy helps Jaha confront his past. Indra makes Octavia an offer she can't refuse.
The alliance between Camp Jaha and the Grounders is jeopardized when Gustus is poisoned. Meanwhile at Mount Weather, Monty lands himself in hot water.
Camp Jaha butt heads over what to do with Finn, as flashbacks show his and Raven's relationship on the Ark.
As Abby and Jaha each try to establish their authority, Clarke comes up with a plan to stop the Grounders' attack. At Mount Weather, Jasper, Monty, Miller and Harper plan their escape, as ...
Tensions run high between Clarke and Finn, and Raven discovers that Mount Weather is interfering with Camp Jaha's communication systems. Meanwhile, Jasper and Monty discover the truth about what's going on at Mount Weather.
While Kane leads a mission to make peace with the Grounders, Jasper agrees to participate in a risky experiment, and Finn's search for Clarke takes a violent turn.
After being betrayed by Anya, Clarke takes matters into her own hands. Meanwhile, Bellamy, Finn, Murphy, Sterling and Monroe race against time to save a survivor of the Ark crash, and Raven struggles to cope with her paralysis.
Clarke and Anya join forces to escape Mount Weather. Kane issues an order to have Abby brutally punished. Octavia searches for Lincoln.
Clarke demands answers from President Wallace, Abby performs emergency surgery on Raven, and Octavia resorts to violence to find Lincoln.
While Clarke struggles to make sense of her bizarre surroundings, Lincoln risks his life to save Octavia, and Kane establishes his authority.
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 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 ...
Clarke and Finn are captured by Anya, who forces them to save the life of a victim of the explosion. Meanwhile, Raven deals with her split from Finn, and Kane fights to save the Ark and it's survivors.
Murphy returns to the camp carrying a horrific virus created by the Grounders to weaken the camp. After learning the Grounders plan to attack the next day, Bellamy, Finn and Raven come up with a plan to delay them.
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.
Shumway secretly orders one of the 100 to kill Bellamy. Meanwhile, hallucinogenic nuts provide Octavia with an opportunity to help the Grounder escape the camp, and Bellamy and Clarke investigate a nearby underground depot, where they find military weapon
While Bellamy tortures the Grounder, Raven and Clarke make contact with the Ark and ask Abby to help them save Finn. On the Ark, Kane deals with his guilt, and Jaha surprises the council with a shocking revelation.
Bellamy, Finn and Jasper head into Grounder territory to search for Octavia, as flashbacks show the siblings' difficult childhood on the Ark. Meanwhile, Raven finds out about Clarke and Finn.
A plan to contact the Ark is put in motion after Raven crash lands on Earth. Meanwhile, Abby exposes Kane's plan to reduce the population of the Ark.
Bellamy, Clarke and Finn try to protect Charlotte when everyone learns she killed Wells. On the Ark, Abby risks getting floated in order to give Raven the chance to launch the escape pod.
As a dangerous, acidic fog approaches, Clarke, Finn and Wells set out in search of a seaweed-like plant to make an antibiotic poultice for Jasper's wounds, while a vulnerable young girl ...
Discovering that Jasper may still be alive, Clarke, Bellamy, Finn, Wells and Murphy head out to find him. On the Ark, Abby is determined to prove Earth is habitable, and enlists a mechanic ...
97 years after a nuclear war, human kind is living in space. 100 juvenile delinquents are sent down to Earth to see if the planet is habitable.