As the Super Friends brave the Phantom Zone to bring Supergirl home, each member of the team is confronted by visions of their worst fear.
Tropes:
- Absurd Phobia: Brainy reveals that he's afraid of balloons. The fact that they could pop at any moment really stresses him out.
- Badass Boast: J'onn, before overpowering the Phantom:I'll show you what it's like to be afraid!
- Bread, Eggs, Breaded Eggs: When J'onn explains that, in their native dimension, the Phantoms give people visions of their deepest fears, Brainy and Alex compare it to a Dementor, or a Boggart, or Harry's Dementor Boggart.
- Continuity Nod: Kelly brings up her first meeting with Alex in a hospital, back in Season 4 when James was shot.
- Foreshadowing: Kelly picks up a shield during her dream, foreshadowing her taking up the mantle of Guardian during the course of the season.
- Heroic BSoD: Kara, affected by the Fear Vision, loses all hope. Her father eventually manages to snap her out of it.
- Heroic Willpower:
- Lena is the only one who manages to figure out that she is in a Fear Vision.
- J'onn takes on the collective fears of his friends and still manages to overpower the Phantom.
- Hero of Another Story: M'Gann is watching over the city while the team is trying to save Kara.
- The Immune: Due to their physiology, J'onn and Brainy are able to withstand being trapped in a Fear Vision, though the Phantom's powers still affect them.
- Not Quite Dead: Nyxlygsptlnz, who hitches a ride towards Earth at the end of the episode.
- "Rashomon"-Style: After a 2 hour jump back, the episode keeps jumping back 10 minutes to show everyone dealing with their fears. Once it reaches J'onn, he's in the real world and his powers provide him a defense against the Phantom. Brainy likewise snaps out of it, as his advanced intellect allows him to compartmentalize his fear.
- Sequel Hook: Nyxlygsptlnz clings to the hull of the ship as it portals out of the Phantom Zone.
- Shout-Out:
- Phantoms are this time directly compared to Dementors.
- The water phantom closing in on Lena not only looks like a Xenomorph, but the shot just before commercial is an almost perfect recreation of the famous shot of the queen slowly moving towards Ripley, who has her head turned towards the camera out of fear.
- Also Lena's fear of death by drowning could also be an allusion to Katie McGrath's character's watery death in Jurassic World.
- "What Do They Fear?" Episode: Alex, Lena, Kelly, Nia and Brainy are all given visions of their worst fears by the Phantom.
- Alex dreams about being infected by a Phantom and unwillingly being the reason they can't save Kara, having to kill herself in the end.
- Lena dreams about her friends being killed by a Kelpie, a mythological, shape-shifting water creature her mother used to tell her stories about, until she drowned.
- Kelly dreams about all of her friends being possessed by the locked up Phantom, only getting through to Alex for a short moment before she loses her again.
- Nia dreams about misinterpreting a vision and Brainy dying as a result.
- Brainy dreams about balloons raining from the ceiling.
- What Happened to the Mouse?: M'gann is mentioned looking after National City while everyone else rescues Kara, but does not appear for the rest of the series, with no dialog indicating that she went back to Mars or anything.
