Plot summary
Clarke returns to camp with knowledge of the only way the grounders will accept a truce. Opinions are divided when Clarke reveals the grounders will cease their attack if they are given Finn. Flashbacks to the Ark reveal that Finn was imprisoned because he took the fall for Raven's illegal spacewalking. At Camp Jaha, Abby and a returned Kane think they can bargain with the grounders by offering to put Finn on trial, but such plans are for naught, as Finn ultimately turns himself in. In a last-ditch effort to save Finn, Clarke goes to meet with Lexa. When Lexa refuses clemency, Clarke asks to say goodbye. She approaches Finn, kisses him, and tells him that she loves him while stabbing him to death, saving him the brutal torture/execution of grounder custom.
Credits
Adapted from Wikipedia contributors, List of The 100 episodes. HTML formatting and reference markers removed.