Abby is determined to find a way to protect her people from a coming attack by the Grounders, even if it means heading into unknown territory and leaving some captives behind. A worried Bellamy convinces Clarke to go with him to the drop ship, where he and Octavia reveal a dangerous secret. Clarke comes up with a bold new plan to stop the Grounders’ attack, leading Abby to a desperate decision. Meanwhile, at Mount Weather, Jasper and Monty begin to question the motives of their new friends, while Dr. Tsing conducts a deadly experiment to determine how to make use of the captives.
Elenco: Eliza Taylor , Bob Morley , Marie Avgeropoulos , Lindsey Morgan , Paige Turco , Christopher Larkin , Isaiah Washington , Henry Ian Cusick , Richard Harmon , Devon Bostick , Ricky Whittle , Thomas McDonell , Alycia Debnam-Carey , Eli Goree , Tasya Teles , Shannon Kook , Zach McGowan , Shelby Flannery , Richard Harmon , Sachin Sahel .