Clarke struggles to survive on a desolate, scorched earth while her friends in space come across a long-awaited beacon of hope.

Octavia is forced to take guidance from an unlikely ally when the future of the bunker and all those inside it is jeopardized.

Bellamy leads the charge investigating a potential way home. Meanwhile, Clarke and Madi deal with the new, uncertain threat to their home.

Our Heroes are forced to rely on the help of Shallow Valley's dangerous new inhabitants in order to save some of their own, with surprising results.

Octavia leads her people towards Shallow Valley against the advice of Clarke and Bellamy. Meanwhile, Kane and Abby adjust to a new set of challenges.

Kane's attempt to prove himself useful tests Wonkru's allegiance to Octavia. Madi faces an unexpected threat inside Wonkru, forcing Clarke to make an unlikely ally.

Clarke and Bellamy make a startling discovery about Wonkru’s battle plans as Echo risks her friendship with Raven to complete her mission.

Clarke’s determination to protect Madi puts Bellamy in an impossible position.

The growing fractures in Wonkru threaten to explode once and for all. Meanwhile, in Shadow Valley, Murphy starts a fire, unleashing catastrophic results.

Monty strives to show Wonkru an alternative to war, and to the valley itself. Meanwhile, Abby’s health continues to deteriorate, along with McCreary’s patience.

As Clarke races to save Abby, she learns more about the trials and tribulations Wonkru faced in the bunker, and the impossible decisions they were forced to make in the dark year.

Octavia leads her people into war. While behind enemy lines, our heroes must overcome their differences to save Wonkru from extinction.

Clarke and her friends must risk everything to fight one last battle for survival, only to glimpse an even darker threat to the last living valley on Earth.

Still reeling after receiving Monty’s message, a small group goes down to explore the mysterious new planet. Back on the Mothership, several members of Wonkru face the consequences of their decisions.

The team on the ground flights to survive the threat they face on the new planet. Meanwhile, Raven must join forces with an unlikely ally to save everyone on board the Mothership.

Clarke tries to win over the leaders of Sanctum in order to let her people stay. Meanwhile, Bellamy, Echo and Octavia discover a new threat while on a mission to retrieve the transport ship.

Clarke embraces the traditions of Sanctum and tries to make amends for her past actions.

Jordan investigates Sanctum. Meanwhile, Octavia and Diyoza discover the threats of the new planet firsthand. Lastly, Bellamy and Clarke butt heads.

Diyoza learns more about the mysterious Children of Gabriel while Abby continues searching for a way to save Kane.

Clarke’s past catches up to her.

Octavia and Diyoza make their way to the mysterious anomaly in search of the Old Man. Meanwhile, Murphy has an offer for Emori.

Bellamy must venture into enemy territory with an unlikely companion. Meanwhile, Octavia is forced to confront her past.

Russell seeks justice. Meanwhile, Gabriel must make a difficult choice. Lastly, the Blake siblings reunite.

Bellamy and Octavia must work together to save their friends. Echo is forced to face her past.

A special Naming Day changes everything in Sanctum. Gabriel comes face to face with an old friend.

Sanctum becomes a battleground between the devout and the non-believers. The mystery of the anomaly deepens.

Clarke and her friends attempt to rebuild Sanctum as a new threat rises in the woods.

Echo and Gabriel learn more about Hope and her mysterious past.

Raven faces an unexpected threat. Clarke must keep the peace among opposing factions in Sanctum.

Mysterious outsiders arrive with news of Clarke's missing people.

Octavia gets to know a whole new world. Meanwhile, Murphy and Emori play make believe.

Clarke and her friends find themselves on a planet that is not what it seems.

Emori tries to heal Sanctum's old familial wounds while Echo, Octavia and Diyoza struggle with new ones.

Clarke confronts a new adversary. A surprising connection takes us back to the past and to the nuclear apocalypse that destroyed the Earth.

Murphy and Indra must defuse a tense situation. Old friends make new allegiances.

Sheidheda makes his move. A Disciple goes rogue.

Where in the universe is Bellamy Blake?

It's a new day in Sanctum. Clarke, Octavia, Raven and Echo struggle with a new foe.

The red sun derails Clarke's plans.

Clarke and her friends reckon with all that has happened only to find an unexpected threat looming.

Clarke and Octavia mount a desperate rescue mission as the Disciples close in on what they want.

After all the fighting and loss, Clarke and her friends have reached the final battle. But is humanity worthy of something greater?