As the Phantoms grow stronger, the team struggles to catch the Prime Phantom before it becomes unstoppable.
Tropes:
- Arson, Murder, and Jaywalking: When arguing for Lena belonging on the team, despite her immense guilt, Alex brings up her willingness to hear others out, her brilliance, and being the only one with a decent taste in Scotch.
- Artistic License – Biology: At the end of the episode, the Superfriends figure out that they need to travel back in time to get a sample of Kara's DNA, since it's one of the few times they know for sure she bled from an injury. Kara may be an alien, but she's still a humanoid and must shed skin cells, have loose strands of hair fall out (like getting caught in her hairbrush or been recently cut off), and so forth. Surely a quick search of her apartment would produce at least one viable sample.
- Comfort Food: Brainy gorges on donuts to deal with his emotions. Nia lampshades it.
- The Corrupter: Nyxlygsptlnz tries to convince Kara to leave her father behind.
- Driven to Suicide: Nyxlygsptlnz refuses to be rescued by Kara after the mirror is smashed, apparently dying in the self-destruct sequence.
- Dwindling Party: J'onn, Brainy, and Nia are all infected by the Phantoms one after the other until Alex manages to reverse it.
- "Eureka!" Moment: When talking about that the Prime Phantom is driven by instinct, Lena has the idea to let it guide them to Kara. And then Nia understands her visions of Midvale, as they'll have to go to the past to get more DNA of hers.
- Evil All Along: Nyxlygsptlnz turns out to have been using Kara to get home, injuring her father, so she can take her revenge upon those who wronged her.
- Faux Affably Evil: Nyxlygsptlnz, once she drops the mask.
- Gonna Need More X: When they see how big the Prime Phantom has grown after imprisoning so many souls and is able to resist the ProtoTrap, Brainy dryly paraphrases Chief Brody: "We're gonna need a bigger gun."
- History Repeats: In "Alex", Maggie and Kara were forced to choose between the common good and their loved one when Alex was kidnapped and the perpetrator wanted them to break out a murderer in exchange for Alex's safety. Here, Lena and Alex have to choose between the many and their loved one when the MacGuffin can be used either to retrieve Kara or to save tons of people from becoming phantoms. Both times, the sister force-chooses the common good, Kara by stopping Maggie from breaking out the murderer and Alex by stopping Lena from using the MacGuffin for Kara. Unlike Alex's rescue, they don't get Kara back anyway.
- It's All My Fault: Lena blames herself for Kara being trapped in the Phantom Zone, as it was her experiments that gave Lex the power to send her there. Her guilt over this causes her to prioritize rescuing her over stopping the Phantoms; Alex has to force the issue.
- I Will Only Slow You Down: Zor-El, after he is injured, implores Kara and Nyxlygsptlnz to go on without him.
- Make My Monster Grow: The Prime Phantom grows larger as it gathers more life forces.
- The Needs of the Many: A running theme. Though means are floated to rescue Kara, all of them hinge upon allowing the Prime Phantom to continue its rampage, which would leave no world for Kara to come home to.
- No MacGuffin, No Winner: Kara smashes the exit mirror to keep Nyxlygsptlnz from using it, since Nyxlygsptlnz promises to make trouble on Earth before departing to her own realm.
- No Ontological Inertia: Destroying the Phantom chrysalis returns all the lost souls to their owners and undo their Phantom transformations.
- No-Sell: The Prime Phantom is so large and powerful that the ProtoTrap can't affect him, even when Dreamer is assisting with her powers.
- Opening Narration: Last used in Season 4, returns in this episode.
- Sadistic Choice:
- Thanks to her split soul, M'gann gains the Phantom ability to sense life force, which means she can track Kara. However, that ability will only last as long as her soul remains split, and if the Phantom's gathered souls reach a critical mass, it will be impossible to stop its invasion. Ultimately, stopping it takes priority.
- Lena comes up with an alternate means of tracking Kara through her Video Will crystal, but the device can only hold one signature at a time and when they need it to find the Prime Phantom, changing targets means Kara's signature will be permanently lost. They choose the latter.
- Save the Villain: Despite hurting her father, lying to her and using her to get home and get revenge, Kara still tries to save Nyxlygsptlnz.
- Sealed Evil in a Can: The Prime Phantom gets trapped and imprisoned at the end.
- Shout-Out: Lena creates a "ProtoTrap" which grabs Phantoms within a wobbly beam of light and imprisons them within a small container. Brainy outright remarks that it's "just like in Ghostbusters", to which Lena retorts that This Is Reality.
- Stupid Evil: Really, if Nyxlygsptlnz had just kept up the facade until they were through the portal, she could have terrorized Earth all she wanted and gotten back to the Fifth Dimension and Kara wouldn't have been able to stop her. But instead she just outs herself as a villain for absolutely no reason.
- Weapons That Suck: Lena's ProtoTrap hits Phantoms with a beam that sucks them in, then teleports them to a containment unit at headquarters.
- What the Hell, Hero?: Alex towards Lena when she basically suggests they endanger tons of innocent people just to get Kara back.
- You Are Better Than You Think You Are: At the end, Lena is worried that she doesn't belong on the team, because she was willing to choose freeing Kara over the imprisoned souls. Alex assures her that that's not the case.Alex: Every moment I was running towards that Chrysalis I wanted to turn around. I didn't care if that Phantom took over the whole city or the whole world. I wanted nothing more than to drop everything and go after my sister. I had to rely on my years of training as a soldier to help me push those feelings aside so that I could do what had to be done. You have a huge heart, Lena. And wanting to save Kara, that doesn't make you any less of a hero.
Lena: Yeah, maybe not. But I still don't think like you.
Alex: Neither does Brainy. Or J'onn, or Nia. I mean, we all have different life experiences and perspectives and strengths. It's our willingness to hear each other out, that's what makes this a great team. And if it weren't for your brilliance in making that device, we all would have failed. You belong here, Lena. You always have and you always will. And besides, you are the only one with a decent taste in Scotch.
