Complete story — includes the ending
When King Roan has Emerson, the last Mountain Man, delivered to Polis, Clarke must decide his fate. Ultimately, she decides to let Lexa banish him. Octavia and Kane find out Pike intends to clear a nearby grounder village and utilize their fertile soil for crops, so Octavia rides to alert the village. The village set a deadly trap for the incoming Sky People, which Octavia manages to warn Bellamy about just in time. Abby confiscates the City of Light chips from Jaha when it becomes clear he has no recollection of his son. A.L.I.E. enlists Raven's help to search the Ark for her second iteration, A.L.I.E. 2.0. They are unable to find it, which leads to the realization that it may be on the mythical 13th station, named Polaris, that got shot out of orbit before joining the rest of the Ark. Titus, the Flamekeeper, tortures Murphy for information, alongside an escape pod with two letters clearly scorched off from re-entry that, with the other marked letters, spells Polaris.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, List of The 100 episodes. HTML formatting and reference markers removed. · Content license