1 | [s1e12] We Are Grounders - Part

: With only 51 hours of life support remaining, Jaha and Kane realize survival on the Ark is impossible. Inspired by old footage of a young Clarke and Wells, Jaha develops a radical plan to pilot the entire Ark station into Earth’s atmosphere. Key Developments & Climax

: After returning to camp, Clarke and Bellamy disagree on strategy. Bellamy gives a rousing speech declaring that they are now "Grounders" and should stand their ground to fight. Clarke overrules him, insisting they must evacuate to the ocean to survive the incoming army. [S1E12] We Are Grounders - Part 1

: Following their capture by Grounders, Clarke and Finn are rescued by Lincoln. During their flight, Lincoln leads them into a mine tunnel system inhabited by Reapers —savage, cannibalistic humans. Lincoln stays behind to distract the Reapers, while Finn is forced to commit his first official kill to save Clarke. : With only 51 hours of life support