"Both Sides Now" is the thirteenth episode of the third season of Supergirl and the fifty-fifth episode overall. It aired on February 5, 2018.


The D.E.O. captures a second World killer, Purity. Supergirl and Alex use very different methods of interrogation with Purity in the hopes of finding out how to defeat Reign. However, Purity escapes and attacks the city’s subway tunnels. Meanwhile, J'onn, Winn and Mon-El band together to fix the Legion ship.


  • Despite being credited, Mehcad Brooks does not appear.
  • The title of this episode might be a reference to the Joni Mitchell album and song of the same name.
  • It also may reference the shocking revelation that Lena Luthor uncovered: her close friend and employee, Samantha Arias being the civilian persona of Reign.
  • Julia Freeman was singing along to Lisa Loeb's single Stay.
  • Mon-El revealed his marriage to Imra Ardeen was political, and part of an arranged marriage, though the two did fall in love along the way.  
  • As of this episode, Supergirl will go on a two month hiatus to make room for DC's Legends of Tomorrow as Black Lightning has taken their time slot.