For the group of superheroes, see The Trinity.
"Reign, Purity, Pestilence, they were all created by Kryptonian witches to do one thing: kill the world. And now that they're together, they're doing that."
Kara Danvers
"Trinity" is the seventeenth episode of the third season of Supergirl, and the fifty-ninth episode overall. It aired on May 7, 2018.


Still reeling after learning about Lena's secret, Supergirl asks Guardian for a favour that could alter his relationship with Lena forever. Meanwhile, with all three Worldkillers united, Supergirl and the team brace for an epic battle.[src]


  • The episode's title refers to the Worldkillers - Reign, Purity, and Pestilence.
  • This is the second episode of Supergirl where Kara Danvers appears only as Supergirl, the first being "Resist".


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