“Human Trials” is episode five of season two of The 100.
At the end of the previous episode, “Many Happy Returns”, Clarke and Anya had finally come to an arrangement to team up against the mountain men of Mount Weather, when the people guarding the sky people’s camp proved a little trigger happy, killing Anya. Which kind of makes a mess of that idea.
Finn is still out looking for the missing people, along with Murphy. Because he doesn’t know about the Mountain Men, he assumes that the Grounders have them, and doesn’t listen when they deny it, assuming that they are lying. Which leads to unfortunate actions that could have nasty consequences.
It turns out that Mount Weather is using the Grounders to filter their own blood when they get radiation poisoning, not for blood transfusions. I wasn’t sure which it was. It doesn’t look that believable though.
Lincoln, who was captured by Mount Weather in “Reapercussions”, is being experimented on by the Mountain Men, although to what purpose isn’t known, and Kane bumps into Jaha.