Lex tasks Supergirl with protecting Andrea from an anti-tech extremist, but his nefarious purpose goes beyond merely keeping Andrea alive. Meanwhile, Lena moves forward with Non Nocere, with Lex's help.
- Animal Testing: Lena is seen testing Non Nocere on two animals before moving to human trials.
- Big Damn Heroes: Nia saves Kara from Amy after the latter has her depowered.
- Blasphemous Praise: Lex praises Lena for using Non Nocere to do what God "couldn't"—that is, suppress the violent impulses of an otherwise vicious animal.
- The Bus Came Back:
- The Totally Radical Brainy who joined the Big Brain comes back, being asked for help by the Prime Brainy.
- Steve Lomeli from "Crime and Punishment" also returns with an important role in Lena's experiments.
- The Cameo: Known voice actor Scott McNeil appears as the prisoner Toby. This was his second minor, prisoner character in an Arrowverse series, following Julius in a Season 1 Flash episode.
- The Corrupter: Lex, albeit in a more Affably Evil sense than normal; right when Lena is wondering if Non Nocere is leading her down a dark path and starts reconsidering her efforts, Lex convinces her that she is doing the right thing and shouldn't care what Supergirl thinks.
- A Day in the Limelight: The episode focuses on Andrea Rojas.
- Desperately Looking for a Purpose in Life: Alex, who realizes that, for the first time after medical school, she is without a superior telling her how to do things. She comes around by the end of the episode with J'onn's help.
- Distinction Without a Difference: Lena doesn't see Non Nocere (suppression of negative emotions) as being the same as brainwashing, feeling insulted that the heroes see it as the latter.
- Elevator Failure: Amy's first assassination attempt is her causing the elevator that Andrea is on to malfunction.
- Everyone Has Standards: Lena maintains that she doesn't want to rid the world of free will, just negative emotions. She also decides to test Non Nocere on volunteers when moving on to human trials, rather than using it on unsuspecting innocents.
- Gone Horribly Wrong: Lena's first human trial on convicts. While it does turn the violent inmate Toby peaceful, the previously picked-on inmate Steve gets uncontrollable desires of revenge. She later fixes it, however.
- Heel–Face Revolving Door: Lena ignoring Kara's ultimatum from the previous episode would seem to put Lena firmly in the villain camp. Yet the episode has Lena wondering if she is doing the right thing. Although she ignores her Heel Realization there are enough hints that the door may not be firmly slammed shut.
- Heel Realization: Subverted; Lena's failed human trials almost make her change her mind about Non Nocere, but Lex manages to convince her that she's in the right and helps her correct the problem she's having with the algorithm.
- He's Back!: Andrea regains the shadow powers she had Pre-Crisis, but of course in her perspective, she's only just learning to use them.
- Human Aliens: Amy, a Chloriphilian, looks completely human.
- I Regret Nothing: Andrea states that she would do all the morally ambiguous things she did to save her family's legacy again.
- Irony: Kara notes how she has been so busy with dealing with Obsidian Platinum that she forgot her own real life. This leads her to reconsider going out with William.
- It's All My Fault: Alex blames herself for not being strong enough without her DEO resources when Amy almost kills J'onn.
- Lack of Empathy: When Brainy points out that Lex's fail-safe endangered the lives of two-thirds of National City, Lex dismisses the potential catastrophe with "so a few houses would have burned down", and feels that there's no real problem, since Supergirl managed to save the day.
- Moral Myopia: Lena is still angry that Supergirl and company assumed that she was trying to brainwash the world when she used Myriad, overlooking that she a) stole a brainwashing device, b) exploited Supergirl's trust to do it, c) never made her intentions clear when she was confronted, and d) wasn't exactly intending to give people a choice about whether to accept Non Nocere. Lena clearly expects a lot of good faith from people she explicitly doesn't trust.
- Morph Weapon: J'onn gives Alex a Martian weapon that can change forms.
- Motive Rant: Lena has one in a quiet moment with Lex.
- An Offer You Can't Refuse: Lex blackmails Supergirl into acting as Andrea's bodyguard by subtly threatening to unveil her secrets.
- Out of Focus: Kelly barely appears in the episode.
- Passive-Aggressive Kombat: Gamemnae and Lex engage in some throughout the episode.
- Pet the Dog: Lex gives Lena a pretty honest-sounding You Are Better Than You Think You Are speech when she is desperate after her first human trial goes wrong. It motivates her enough to fix the mistake.
- Power Fist: Amy has some very powerful gauntlets that even allow her to De-power J'onn and Kara.
- Redemption Rejection: Lena has again rejected all attempts to come back to the light, and is determined to deprive people of their negative emotions.
- Red Herring: Todd Sapphire is not the assassin; he committed suicide after becoming addicted to Obsidian. His wife, Amy, is the real culprit.
- Samus Is a Girl: The assassin is a woman, Amy Sapphire.
- Series Continuity Error: Lena states that Non Nocere is not about brainwashing people or forcibly removing their base instincts and she will only test on volunteers. Yet she gave Eve no choice when she body jacked her with Hope and was happy to use Myriad to launch Non Nocere on an unsuspecting world (one wonders if this has been done by the writers to try and make Lena's actions less out of character).
- Shipper on Deck: Alex again convinces Kara to go on a date with William.
- The Stinger: Lex sealing an alliance with Gamemnae aka Gemma Cooper, being ready to meet Leviathan, in order to get close to and defeat them.
- Talking the Monster to Death: Unable to physically stop Amy, Kara appeals to her better nature before she blows up Obsidian Platinum's energy source. She succeeds.
- Tragic Villain: Amy, full stop. Her husband drifted away from her due to his addiction to Obsidian, which culminated in him committing suicide. Everything she does is to stop Obsidian Platinum from launching and prevent anybody from experiencing the same pain as her, damn the consequences.
- Villain Has a Point: Supergirl concedes that Amy's manifesto has a lot of good points in it.
- We Used to Be Friends: Lena has decided to go down the villain route, and she openly states that Kara and her friends are nothing to do with her anymore. Tellingly, she is still referring to Supergirl and refusing to call her Kara.
- Well-Intentioned Extremist: Lena, Andrea, and Amy all have good intentions (Lena's trying to suppress humanity's negative qualities, Andrea wants to preserve her father's company and improve life for people; and Amy wants people not to lose themselves to virtual reality), but they're willing to use amoral means to get there.
- What the Hell, Hero?: Brainy confronts Lex on his fail-safe, which endangered a huge portion of the city. Naturally, he doesn't care much.
