"On Argo, we learn from Krypton's mistakes. We look to our past for edification. My mistakes were the biggest of all."
Alura Zor-El
"Dark Side of the Moon" is the twentieth episode of the third season of Supergirl, and the sixty-second episode overall. It aired on May 28, 2018.


Supergirl is stunned to discover that a part of Krypton survived. Meanwhile, Alex is attacked while out with Ruby, and Lena considers how far she will go to keep Reign contained.[src]


  • Argo City is Supergirl's home city in the comics. It also appeared in 1984's Supergirl, and is from where Kara arrived on Earth in search of the Omegahedron.
  • Selena being given the vote to break the tie to give away a piece of the Harun-El to Kara is similar to when Jor-El is given the responsibility to break the tie to put Zod in the Phantom Zone in the 1978 movie Superman.
  • The little boy who Mon-El heals in Argo City is named Val. Though not directly related to Supergirl, Kara's great-great grandfather, Val-El, appears in the series Krypton.
  • Winn mentioned that he has 6 satellites monitoring Supergirl and Mon-El and had his radio dialed up to 11. Winn later says, "Better crank that baby up to 12." This is a quote from This Is Spinal Tap, a 1984 American rock mockumentary.
  • When talking about people she arrested/helped arrest in her past, Alex mentions Ronald Collins and Rick Malverne.
    • Interestingly, Alex never considers Samuel Bernard as a potential suspect, despite the fact that she got him arrested after outing his illegal love affair with Josie to the authorities and Samuel would've been out of prison by 2018 if still alive.
      • This could mean Samuel has since died.


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