Favorite parts: everyone's hallucinations/psychosis, particularly everything with Clarke, Bellamy and Murphy; and the flashback.
What surprised me: that Murphy was unaffected - but then I realized it made perfect sense. I think that the toxin plays on repressed negative feelings, but Murphy is the only one who doesn't repress anything like that - he usually voices all the negativity and bitterness directed at others and himself, so he was fine. The more people are repressing negative emotions, the more they came out full force.
What will happen next: well, I know some of the things from the trailers, promo and Jason's interviews. My impression is that Russell's people are elitist, self-righteous a-holes who decide that only some are 'worthy' to live in their "Paradise". But it's interesting that "Lightbourne" means something very similar to "Lucifer" (or vice versa - the latter is "light bearer"). This doesn't exactly scream trustworhy good guys, and neither does the attitude we see from the trailer, or the fact that they dress like people from the Capitol and live in something that looks like a castle from a Renaissance Fair.
I also think that there is some kind of cloning/genetic modification going on - going by the name of the next episode, the fact that Josie's boyfriend Dr Gabriel Santiago was a geneticist, his remark about embryos, and the fact that the hijackers find dead bodies so important (I don't think it's just the normal reverence for human remains). But if they have been trying to replicate dead humans for two centuries (since Sean Maguire's character killed so many of the members of the mission), they have to have some sort of a method of transferring consciousness, too, because otherwise, clones are just like identical twins, not the same people.
It seemed to be more of a filler episode, however, it still introduced the dangers of the new planet nicely. Fantastic acting, but that’s every episode. Honestly I’m just super excited to meet the new group of people in sanctum.