“Spacewalker” is episode eight of season two of The 100.
At the end of the previous episode, “Long Into an Abyss”, Clarke had got Lexa, the Commander of the Grounder forces, to agree to a truce, after they had cured Lincoln, but with one condition – they have to hand Finn over to them.
The Grounders want to punish Finn for his slaughter of Lincoln’s village in “Human Trials”. ‘Punish’ in this case meaning ‘torture to death.’ Clarke and the others are not happy about this, although many of the crew of the Ark think they should hand over one criminal in order to stop the war.
There are flashbacks through the episode of events a year prior, showing how Finn came to be convicted – which gives a hint as to how some events will turn out.