Luna isn't the only one of her group of oil rig-dwelling Grounders suffering from radiation poisoning. A little girl is also suffering from it, and by the looks of it, doing poorly.
Whatever they're discussing, it seems really serious and dire, based on the expressions on our heroes' faces. Perhaps it has something to do with Luna and her people looking so rough.
Since the hydrogenerator plan was a bust, perhaps they're working on coming up with a new alternative to keep their people alive through the nuclear meltdown.
Bellamy made a difficult decision on "Heavy Lies the Crown," choosing to destroy the hydrogenerator in order to save his enslaved people. Will he eventually regret that choice?
Bellamy is one of the few people that Clarke let in on the end of the world secret. While the title of this hour, "Heavy Lies the Crown," might seem to refer to Roan, it can also be applied to both Bellamy and Clarke – as the de facto leader of Skaikru, they must often make the hard choices to keep their people alive.
Bryan followed Pike out of gratitude that the ruthless, anti-Grounder dictator had kept their people alive after crash-landing in Ice Nation territory. Bryan's anti-Grounder tendencies may cause issues in his relationship with Miller.
After months apart, Miller reunited with his boyfriend Bryan last season. Unfortunately, they had some friction over Bryan's allegiance to Pike. Now that Pike is out of the picture, will their relationship recover?
Monty has survived the loss of his father and having to kill his own mother after she was chipped. Will he and his newfound love Harper manage to survive the literal end of the world?
Bryan: Are we ever gonna be done fighting? Miller: Hell yes. We're gonna build a house on a lake. We're gonna plant corn. And raise chickens. And grow old.