Junior in those circumstances was like the lead character in The Deer Hunter (1978 movie starring Robert De Niro), maladjusted in normal times, but those same intense traits made him a hero in crazy times, such as the war in Vietnam. Junior is a psycho in "normal" times under the dome - though of course nothing can be completely or even mostly normal under the dome - but rises to the even crazier occasion of people pent up in the clinic, and masterfully talks them down.
All of this is going on with pretty Angie still chained in Junior's basement, and water gushing into it no less. This is the underside of Junior - literally - a foundation of his insanity that he is unwilling to remove or change.
Fortunately for Angie, and in a good move for the story, Junior's father Big Jim finally hears Angie screaming at the end of the episode, and finds her in the basement. Bad news for Junior, especially ironic because it happens right after Big Jim comes to see some value in his son, and even says he should consider a career in law enforcement.
What will Big Jim do? Given what little we know about him, I'd say the thought might occur to him to kill Angie to protect his son. On the other hand, he has even more motive to dispose of Rev. Coggins, and thus far has refrained. Maybe he'll split the difference, and just not release her from the basement.
Meanwhile, Julia's antipathy to Barbie is growing to the point that she's barely grateful that he saved her life - almost as if she senses that he killed her husband. But I'm still thinking that we'll see them in bed together - if not in this season, before the series is over.