"Ahimsa" is the fourth episode of the fourth season of Supergirl, and the sixty-ninth episode overall. It aired on November 4, 2018.


When Supergirl needs help, Alex asks Lena and Brainiac to team up. Meanwhile, J’onn questions his decision to quit the DEO. However, after running into Manchester Black, he realizes there are a lot of ways to help his fellow aliens during this tumultuous time.


  • The episode's title, "Ahimsa", is a phrase meaning "nonviolence" in Sanskrit. It is an essential religious principle of Jainism and aspect of nonviolent resistance. It is used in the episode by Fiona.
  • While Kara is recovering in her protective suit, Brainiac says, "If you're in your mind palace, say 'Hi' to Streaky for me." This is a reference to the events of the episode "Legion of Super-Heroes".
  • What Lena Luthor says to Brainiac, another person 'Perenna' tells Jennifer from 'Black Lightening' to make boxes and put her feelings into them, so that Jennifer to help her to learn to better control her new meta-human abilities.


  • In one scene with Brainy, Lena expresses her anger that one of her inventions has been hijacked to hurt someone, but the dispersal device isn't technically her invention; it was Lex's, as a weapon with which to kill Superman. With Winn's help, all Lena did was adapt it to disperse lead, as a "last resort" means of defeating Rhea and the Daxamites.