In Shallow Valley, Abby is still administering treatments to select miners in secret. Diyoza sends only her trusted lieutenants to be healed, not because she wants everyone else to die... she just really, really wants McCreary to die! Once he succumbs to his advancing illness, she fully intends to let everyone else gets treated. Unclear whether her hatred of him is 100% personal, as he also seems to be her only rival for command.
One point working in her favor is that Vinson, the scariest dude in the camp, definitely scares McCreary, so keeping him nearby has helped protect Abby and the secret cure. Because Abby cured Vinson first, she's earned his loyalty, such as it is... but Diyoza cautions her not to get too comfortable around him because he's still a wild beast. (I completely love Mike Dopud's performance as Vinson. He's understated, exhibits incredible self-restraint, yet is clearly capable of monstrous acts.)
Nearby in the captives' cabin, there's a bit of an argument about whether Shaw is of more use dead or alive. Fortunately for him, Raven wins that debate. She convinces her team that a more subtle maneuver would be to use the camp's internal division to cause a riot, under cover of which they could all escape. Never one to waste time thinking when action could be taken, Murphy immediately starts whispering in miners' ears to light the fuse. Then he goes to find McCreary and confirms what McCreary had suspected; a cure is being given to some, but not all. At the same time, Echo hurries to tell Diyoza that McCreary knows, and fit's about to hit the shan.
Diyoza makes a good attempt at quelling the riot McCreary is trying to start, but Murphy throws a rock to set things off, and we get a badass pregnant woman fight scene. Seriously, Diyoza is five months pregnant, and she kicks so much ass! (I'm four months myself and get winded after a couple of flights of stairs.)
During this fight comes the completely unsurprising reveal that McCreary is the father of Diyoza's unborn baby. I mean, he's surprised to learn she's pregnant, but I'm in no way surprised he's the father.
Kane shows up to help, wounding but not killing McCreary. It's time to make their escape, but Abby is missing, captured by McCreary and his goons. Obviously, Kane goes after her. Less obviously, Murphy feels he must help... it wasn't long ago (storywise) that Abby was going to use Emori as a medical test subject and possibly kill her...but I guess Murphy has mellowed over the six years between seasons.
So that's what's up in the valley. Now, Polis is a much more messed up story.
As planned, Indra attempts to use Octavia's coma to take control of Wonkru and lead them on a path to peace. But it goes sideways instantly because Miller points out that Indra isn't in command of the army, he is, which technically makes him the acting commander, and the army is still ready to act on Blodreina's standing orders to march to war.
There's now only one way to stop the war...a true Commander must ascend. Clarke is in chains still, awaiting execution, and Madi knows that her only shot at preventing that is to take the Flame. It's powerful to watch her make this choice because Clarke has so poisoned her against the idea of ascending (and she was clearly raised to fear Flamekeepers even before meeting Clarke). The Ascension horn blows, and people all over Polis start losing their shit. Clarke is ready to chew her hand off at the wrist to get out and stop this from happening. Octavia awakens and identifies Bellamy as her attacker, so Indra has to kill a guard, knock out Jackson, and keep Octavia hostage until the Ascension can be completed. Niylah comes at Clarke, accusing her of trying to undermine Blodreina.
And this is where Clarke loses me. She immediately rats out Bellamy and Indra to Niylah, over the poisoning plot and the Ascension. She's desperate to stop this at all costs, so Niylah frees her to help.
Clarke gives Niylah the slip and goes after Octavia with a gun. O is weakened still, so Clarke has a chance here...but for some reason, she's more afraid that Blodreina's followers will reject a true Commander and kill Madi than of any of the much more likely scenarios. She makes a deal with Octavia and escapes with Madi while Bellamy, Indra, and Gaia are arrested for treason and sent to die in the arena.
When Madi awakens, she instantly proves the Ascension was successful, and one of Blodreina's guards falls to his knees before her, but it's not good enough for Clarke. She shoots the poor guy and drives off, abandoning all her friends to die, including the ones in the valley, where Octavia still intends to deploy a bioweapon.
Early in the episode, Vinson said to Abby, in an attempt to comfort her about withholding treatment, which letting someone die is not the same as killing them. That's a poisonous lie that Clarke apparently let herself believe as well. She had a gun on Octavia and couldn't pull the trigger, but she's willing to let everyone else she cares about die in order to follow her own ideal parenting plan for Madi.
I'm betting Gaia bites it in the arena (we saw her training new Flamekeepers, so her purpose is less unique now), but please let something happen to stop the fight after that! I can't lose Indra or Bellamy, and I'm certain it would never be Bellamy to fall.