All of the official season four summaries of The 100.
04×01 Echoes Aired 2.1.17
SEASON PREMIERE — Clarke (Eliza Taylor) and her friends struggle with how to proceed after the fate of the world is revealed. Paige Turco, Bob Morley, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Dean White directed the episode written by Jason Rothenberg (#401). Original airdate 2/1/2017.
04×02 Heavy Lies The Crown Aired 2.8.17
CHALLENGES — The burden of leading weighs heavily upon Clarke (Eliza Taylor) and Bellamy (Bob Morley) when different challenges force them to determine who will live and die. Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Ed Fraiman directed the episode written by Justine Juel Gillmer (#402). Original airdate 2/8/2017.
04×03 The Four Horsemen Aired 2.17.17
TENSIONS RISE — Jaha (Isaiah Washington) leads Clarke (Eliza Taylor) and Bellamy (Bob Morley) down a road to possible salvation while tensions rise in Arkadia and Polis. Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. P.J. Pesce directed the episode written by Heidi Cole McAdams (#403). Original airdate 2/15/2017.
04×04 A Lie Guarded Aired 2.22.17
ABBY SEARCHES FOR ANSWERS — Continued struggles with leadership and trust in Arkadia and Polis take violent turns while Abby (Paige Turco) leads a team to a distant location hoping to find answers. Eliza Taylor, Bob Morley, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Ian Samoil directed the episode written by Kim Shumway (#404). Original airdate 2/22/2017.
04×05 The Tinder Box Aired 3.1.17
CLARKE MAKES A DESPERATE PLEA — Clarke (Eliza Taylor) makes a desperate plea with a former allied force in an attempt to avoid a war and ensure the survival of her people. Bob Morley, Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. John F. Showalter directed the episode written by Morgan Gendel (#405). Original airdate 3/1/2017
04×06 We Will Rise Aired 3.15.17
CLARKE AND ROAN WORK TOGETHER — Clarke (Eliza Taylor) and Roan (Zach McGowan) must work together in hostile territory in order to deliver an invaluable asset to Abby (Paige Turco) and her team. Bob Morley, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Isaiah Washington and Henry Ian Cusick also star. Dean White directed the episode written by Charmaine DeGrate (#406). Original airdate 3/15/2017.
04×07 Gimme Shelter Aired 3.22.17
THINGS TAKE A TURN FOR THE WORSE — Clarke’s (Eliza Taylor) arrival on the island quickly takes a turn for the worse. Meanwhile, Bellamy (Bob Morley) tries to avoid further tragedy in Arkadia. Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Tim Scanlan directed the episode written by Terri Hughes Burton & Ron Milbauer (#407). Original airdate 3/22/2017.
04×08 God Complex Aired 3.29.17
JAHA FINDS A LEAD — After a disappointing discovery, Clarke (Eliza Taylor) and Abby (Paige Turco) question how far they’re willing to go. Meanwhile, Jaha (Isaiah Washington) finds a lead to the mysterious Second Dawn. Bob Morley, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan and Henry Ian Cusick also star. Omar Madha directed the episode written by Lauren Muir (#408). Original airdate 3/29/2017.
04×09 DNR Aired 4.26.17
CLARKE STRUGGLES TO KEEP THE PEACE — Jasper (Devon Bostick) and Bellamy (Bob Morley) go on a quest. Meanwhile, Clarke (Eliza Taylor) struggles to keep the peace after word of Jaha’s (Isaiah Washington) discovery spreads. Paige Turco, Marie Avgeropoulos, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan and Henry Ian Cusick also star. Mairzee Almas directed the episode written by Miranda Kwok (#409). Original airdate 4/26/2017.
04×10 Die All, Die Merrily Aired 5.3.17
OCTAVIA FIGHTS FOR SURVIVAL — Octavia (Marie Avgeropoulos) fights in the final battle for her people’s survival, but not everyone is willing to play fair. Eliza Taylor, Bob Morley, Paige Turco, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Dean White directed the episode written by Aaron Ginsburg & Wade McIntyre (#410). Original airdate 5/3/2017.
04×11 The Other Side Aired 5.10.17
HENRY IAN CUSICK DIRECTS THE EPISODE — Clarke (Eliza Taylor) faces the consequences of her fateful choice. Bob Morley, Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick also star. Henry Ian Cusick directed the episode written by Julie Benson & Shawna Benson (#411). Original airdate 5/10/2017.
04×12 The Chosen Aired 5.17.17
CLARKE LEADS A GROUP TO SAVE A FRIEND — Jaha (Isaiah Washington) and Kane (Henry Ian Cusick) disagree over how to handle their grim reality. Meanwhile, Clarke (Eliza Taylor) leads a group to save a friend. Bob Morley, Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan also star. Alex Kalymnios directed the episode written by Aaron Ginsburg & Wade McIntrye (#412). Original airdate 5/17/2017.
04×13 Praimfaya Aired 5.24.17
SEASON FINALE — It’s a race against the end of the world as Praimfaya arrives forcing our heroes to make impossible decisions to ensure their survival. Eliza Taylor, Bob Morley, Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick star. Dean White directed the episode written by Jason Rothenberg (#413). Original airdate 5/24/2017.