Kara and J'onn go to Mars, and are surprised to learn that J'onn's father is alive. Meanwhile, Maggie's father comes to town for her bridal shower.
Tropes in this episode:
- Abusive Parents: Maggie's parents were of the emotionally abusive kind. After they found out she was gay, her father pawned her off on her aunt, while her mother removed all her pictures from the family photo albums.
- Amplifier Artifact: The Staff of K'lar amplifies the psychic abilities of Martians considerably. It also works as a Disintegrator Ray when wielded by Supergirl.
- Anti-Hero: Till'all, the young White Martian in the resistance, is willing to use Mind Rape on J'onn's father in order to get to the Staff of K'lar, and has quite the hostile temperament in general. He mellows out a bit by the end of the episode, however.
- Author Filibuster: Maggie's father says "they're building a wall to keep us out, because to them we're nothing but rapists and murderers!" The Speaker of the U.S. House in the Supergirl universe did advocate for building a wall in a previous episode, although this was clearly meant to be critical of President Trump's statements and plans to do just that when this had aired.
- Bilingual Bonus: This episode makes it clear that Maggie isn't just ethnically Latina; she also speaks fluent Spanish and her full name is "Margarita."
- Bittersweet Ending: J'onn and his father are reunited, but Maggie and her father are still on horrible terms and her relationship with Alex will clearly be strained by Maggie not wanting kids.
- Cain and Abel: The two sons of the Martian God H'ronmeer in the Martian myth, Phobos and Deimos. Phobos was the ancestor of the White Martians, while Deimos was the forefather of the Green Martians.
- Calling the Old Man Out: Maggie makes it clear to her father that she's no longer the scared little girl that seeks his approval.Maggie: That little girl, so desperate to win her father's love... you left her on the side of the road. And after all these years, I've been that little girl. Yearning for my papi to come back for me, praying that one day he would see me and love me for who I am. Thank you for coming to the shower, you gave me an amazing gift. You showed me that I'm not that scared little girl in that picture anymore. I'm an adult woman, and I'm happy in my own skin, and I'm so fortunate that I'm surrounded by people who value and cherish me. I finally understand that I don't need you to see me or to get me or to even like me, I don't need anything from you! I'm already good. Good bye, papi.
- Cassandra Truth: When J'ohn first meets his father in his cell, M'yrnn initially thinks he is just a White Martian who has taken the form of his dead son and is pretending to be him, and believes that his real son would never have fled. Once he views J'ohn's memories of his old home and family, he finally realizes he is his son and apologizes for not believing him.
- Casting Gag:
- J'onn's father is played by Carl Lumbly, who voiced J'onn in Justice League.
- To a much lesser degree, Maggie's father seems particularly impressed with Alex being a federal agent.
- Central Theme: The relationship between fathers and their children, reflected in both J'onn's attempts to get through to his father and Maggie's attempt at reconciliation with hers, and even in the tale of H'ronmeer and his sons.
- Chekhov's Gun: Kryptonian immunity to Martian telepathy allows Supergirl to remain unaffected by the Staff of K'lar when the White Martians disable everyone else with it.
- Cool Car: J'onn's Martian spacecraft can shapeshift into a vintage convertible to disguise itself on Earth.
- Cruel to Be Kind: How Maggie's father tries to justify his homophobia; as a Mexican immigrant, he had to earn the respect of his neighbors and coworkers and Maggie being Mexican and a lesbian puts a target on her back. Maggie doesn't buy it, and is incredulous to learn that's his justification.
- Defiant Captive: M'yrnn has been locked up and tortured for over two centuries, but still hasn't been broken by his captors.
- Despair Event Horizon: M'yrnn breaks down at the sight of his old home. Thankfully, he earns back his faith after realizing that J'onn really is his son.
- Dumb Blonde: Kara pretends to be one to a group of White Martians, even though their main question would be what a human was doing on Mars.
- Even Evil Has Standards: Genocidal monsters they may be, but their religious scruples mean that not even the worst of the Whites would kill the Prime Servant of H'ronmeer.
- Fate Worse than Death: How J'onn describes his father's fate as a prisoner.
- A Form You Are Comfortable With: Green Martian society actually has this as a rule. When they are hosting another species, they take a form that makes the guest comfortable. M'yrnn cites this before shifting into human form to mimic J'onn's choice of disguise. It seems that the White Martians have a similar rule, or the resistance fighters choose to abide by it, given that they spend nearly the whole episode as humans.
- He's Back!: After being sulky for the past two episodes, Kara driving J'onn's car blaring "...Baby One More Time" asking for directions from the White Martians prove she's back to her old bubbly self.
- How Did You Know? I Didn't: Supergirl sees two White Martians fighting and punches one of them. When Till'all shapeshifts into a recognizable form and asks how she knew which one to hit, she admits she didn't.
- It's All About Me: Maggie's father says that his homophobia is rooted in belief that the world will not accept her, but his speech about how hard he worked to earn the respect of his racist peers, and that he told his daughter how she "shamed" him when she was first outed, show his main concern is how having a gay daughter makes him look.
- "Just So" Story: The story of the Staff of K'lar explains the origin of the Green and White Martians.M'yrnn: Mars was once a paradise. But H'ronmeer wanted to test his sons Phobos and Deimos, to make sure they were worthy of it. So he offered them two gifts...
J'onn: The Book of Sacred Symbols, the morals that govern Martian life... and the Staff, a weapon.
M'yrnn: The Symbols could be shared, but the Staff wielded by only one.
J'onn: Deimos chose the Symbols... Phobos chose the Staff. He was the first White Martian.
M'yrnn: H'ronmeer was furious that his son would choose destruction over knowledge. And so Phobos was banished to The Underworld... but his descendants clawed their way back and slaughtered my people! - Mood Whiplash: The emotional, tear-jerking scene of M'yrnn and J'onn reliving old memories and falling into each others arms crying is followed by... Kara making a Bugs Bunny reference while driving up in J'onn's car towards a bunch of White Martians, with "...Baby One More Time" playing.
- No Man Should Have This Power: The Staff of K'lar is ultimately deemed too powerful for either the White Martians or the Resistance to have, so J'onn and Kara take it back to Earth.
- Passing the Torch: Metafictionally. Who better to play the father of J'onn J'onzz than the man who for many years was the voice of J'onn J'onzz himself?
- Real After All: J'onn always believed that the Staff of K'lar was just a parable. It turns out to be a very real and very powerful psychic weapon.
- Ripped from the Headlines: Maggie's father made a retort that the country is building a wall to keep Mexicans out because they're seen as rapists and murderers, and the only thing hated more than Mexicans are homosexuals. Also counts as Reality Subtext.
- Secret Test of Character: What lies at the heart of the Martian creation story. When H'ronmeer gave his sons the choice between the Book of Sacred Symbols and the Staff of K'lar, he wanted to see if either of them would be tempted by the power of destruction. Phobos failed the test.
- Shout-Out: Distracting the White Martians by halfheartedly pretending to be a lost tourist, Kara jokes that she "took a wrong turn at Albuquerque."
- Throw the Dog a Bone: Last year, J'onn initially thought that he wasn't the only Green Martian left when he met M'gann, only to find out she was actually a White Martian, making him still the last Green Martian. This time, it turns out there really is another—his own father.
- Unperson: Once Maggie was kicked out of the house, her mom removed her pictures from the family albums.
- "Well Done, Daughter!" Girl: Even after being disowned by him, Maggie still held her father in high regards for years because he was a great dad before he found out about her homosexuality; its implied the reason she became a cop was because he was also in law enforcement. At the end of the episode, however, she has grown out of trying to win his approval.
- We Need a Distraction: Supergirl drives up to the White Martians in J'onn's convertible and acts like a lost tourist, allowing the Resistance to get behind them.
- What Measure Is a Mook?: Despite her general Thou Shalt Not Kill policy, Kara takes no issue with casually vaporizing a bunch of White Martians. In fairness, they were perfectly willing to kill her, J'onn, and the rest of the Resistance, and she did make the choice to detonate the lead bomb which killed Rhea. Even so, for someone who pleaded to J'onn to spare the Martian that was trying to kill him (and who later in the season will go to great lengths to prevent Imra from killing Pestilence), it seems a little out of character for her to so blatantly kill her enemies without so much as a comment on the fact. In fact she's downright cheerful afterwards.
- Wrong Turn at Albuquerque: While distracting the White Martians, Supergirl invokes this trope by name."Hi! Uh, I'm sorry to bother you during...whatever it is you're doing, but I think I took a wrong turn at Albuquerque, and, uh, could any of you give me directions back to Earth? [the White Martians roar at her] Y'know, I thought I took that tunnel, but my GPS is all screwed up down here, and it keeps trying to get me to make this suicidal left turn. You might wanna check your rearview."
- Yank the Dog's Chain: Maggie convinces her deeply homophobic father to attend her bridal shower with Alex and he seems to be making an effort to be understanding (her mother, by comparison, wouldn't even try), only to have him promptly walk out upon seeing them kiss.
