Sanctum becomes a battleground between the devout and the non-believers. Clarke and co fight for control over the Mothership. The mystery of the anomaly deepens.
This episode contains examples of:
- All for Nothing: Octavia suggests this is why the Adjusters are still serving the Primes as if they accept the truth (that they've been nothing but hosts for a pack of selfish people, not serving gods), their entire lives have been for nothing.
- Battle in the Center of the Mind: The struggle between Madi and Sheidheda is presented as this. He's clearly winning, with Madi pinned down on a table as he's strangling her, only to vanish when the Flame is deactivated.
- Bluff the Impostor: When Simone claims to be Abby surviving using the neural mesh, Clarke immediately has one simple question: “What’s my father’s name?”. It proves to be her undoing.
- Brainwashed: Possibly done to Jordan. Earlier in the season, he hated the Primes for replacing Delilah with Priya. After the Adjustment Protocol, he asks Bellamy if taking down the Primes was really a good thing, is holding on to a mind drive, and accuses him of getting Priya killed.
- Cliffhanger: Two, setting up for the next and final season:
- Sheidheda has been removed from the Flame, saving Madi, but escapes, possibly to take over the Eligius IV ship.
- Diyoza's previously unborn daughter, Hope, comes out of the anomaly as an adult. She talks to Octavia, who recognizes her even though she remembered nothing from her time in the anomaly just minutes before. Hope stabs Octavia in the stomach then passes out. Bellamy tries to hold Octavia up as she's bleeding out, until the anomaly comes in to the room and she disappears in a flash of green.
- Didn't Think This Through: This is said by Indra word by word as she points out that the Lightbournes could have put more thought into their plan to take Eligius IV. Russell, Simone, and Clarke posing as Josephine threaten to kill Raven, Madi and Gaia if Wonkru doesn't allow the primes to take the ship, only for Indra to answer that, if the Lightbournes kill them, she and the other Wonkru warriors can simply kill them in retaliation and they would accomplish nothing as their mind drives could be easily destroyed by Wonkru. It never occurs to Wonkru that because Raven, Madi and Gaia are on their knees, their guns being already aimed means they could easily gun down the Lightbournes without any risk to either themselves or the hostages, making their actions a Stupid Surrender as detailed below.
- Indra: If you kill them, we kill you. You didn't think this through.
- End of an Era: For Gaia and the remaining Grounders at least; the Flame chip is completely wiped and disabled in order to save Madi's life.
- Enemy Mine: Russell intends to capture Madi to kill her as revenge for Clarke killing his family. When he realizes that Madi is possessed by Sheidheda, his plan changes to this.
- Even Evil Has Loved Ones: Despite everything we've seen him do recently, Russell truly loves his family. He barely keeps from breaking down when he realizes that Josephine is gone for good. Even Clarke recognizes this, telling him and Simone that she's sorry about their loss.
- Fighting from the Inside: Madi, against Sheidheda. She doesn't do so well, only taking control when Clarke is about to shoot herself and only maintaining control long enough to order her soldiers to take Russell hostage.
- Functional Genre Savvy: Russell, realizing that Madi is not herself. Justified in that he’s spent nearly two centuries transplanting personalities into new bodies, so he’s used to people changing drastically.
- Heroic RRoD: When Clarke tries to cut the Flame out of Madi’s head, her hands are shaking way too much to do it. Considering she’s just seen her mother die, killed a half-dozen people (including the woman who took over her mother’s body), almost shot herself, and is watching her daughter dying on an operating table, it’s not surprising. She ends up having to pass the scalpel to Jackson, who is trained as a doctor, to save Madi.
- Hope Spot: For a moment, it seems as though Abby has come Back from the Dead using the neural mesh, just like Clarke did. However, despite Clarke badly wanting to believe this, she had been there when Russell explained only a few minutes ago that he had disabled Abby's mesh to prevent this. After a simple Bluff the Imposter ("What's my father's name?"), she confirms it's just Simone trying to trick her.
- Human Notepad: After taking her jacket off, it’s discovered that being in the anomaly did this to Octavia. Gabriel recognizes the writing as being from the anomaly stone, leading them back there. Hope also has some of this on her face when she appears.
- "I Know You're in There Somewhere" Fight: After Sheidheda allies with Russell and demands that everyone kneel, Clarke gives in immediately. She pulls out a gun and threatens to shoot herself, begging and pleading with Madi to take back control over her body. She has her finger on the trigger and has counted down to two when Madi takes back over and orders Wonkru to take Russell hostage.
- Recognition Failure: When Murphy, disguised as Daniel Prime, is freeing some prisoners, one of the Adjusters (apparently a lover to Daniel) suddenly starts making out with him, only to be brushed off with a confused "maybe some other time." Murphy later tries to pass this off as Resurrection Sickness, but at least one other Adjuster realizes that "Daniel" is a fraud.
- Revenge by Proxy: Since Clarke killed his family, Russell intends to kill hers, kidnapping Madi. When he discovers she's possessed by Sheidheda, who wants to take over Sanctum himself, plans change.
- Screw This, I'm Out of Here!: With Sanctum in chaos, Russell and the Primes' new plan is to leave entirely and settle on one of the hopefully-habitable planets in the Eligus database with the mind-wiped Wonkru.
- Soap Opera Rapid Aging Syndrome: For the last two seasons, Diyoza has been pregnant. At the end of this episode, her daughter Hope comes out of the anomaly as an adult.
- Stop, or I Shoot Myself!: Clarke puts a gun to her head in a desperate attempt to break through to Madi, tearfully admitting that she can't bear to lose both her mother and daughter on the same day.
- Stupid Surrender: The primes (and Clarke) arrive at the Eligius IV airlock with their hostages on their knees in front of them. In spite of having superior numbers and perfectly clear shots, the Wonkru group still surrenders.
- Thrown Out the Airlock: How Clarke kills the remaining Primes (except for Russell).
- Was It Really Worth It?: Towards the end, Clarke begs Bellamy to tell her that trying to live up to Monty's "be the good guys" was worth losing her mother, in addition to all the other devastation.
- Would Hurt a Child: Russell kidnaps Madi and turns on the radio, intending not only to kill her, but to make Clarke listen while he does.
