“We Are Grounders: Part 2” is episode thirteen of season one of The 100 and the season finale.
In the previous episode, “We are Grounders: Part 1”, the Grounders were finally planning on attacking the 100. The Ark has come up with a way of saving at least some of the people on board it – by deliberately crashing most of it into the ground. Not the best solution by far, but I suppose a semi-controlled crash and possible fiery death is better than definite death from lack of resources and functioning equipment.
Lots of fighting, mostly in the dark, and quite a bit of self-sacrifice, and Clarke comes up with a rather brutal way of dealing with the Grounders. Something that has been referred to in passing – the Mountain Men – make their rather surprising appearance.
Still pretty much a cliffhanger ending, but at least why the Exodus ship crashed in “Unity Day” may finally be guessed. The story continues into season two.