Reign

If you're looking for the "Supergirl" character of Reign, see Samantha Arias.

"Reign" is the upcoming ninth episode of the third season of Supergirl, and the fifty-first episode overall. It will air on December 4, 2017.

Synopsis
Supergirl investigates a mysterious symbol popping up all over National City, tracing its origins back to an ancient prophecy and the mark of the World Killer, Reign. Meanwhile, the tension between Lena and Morgan Edge continues to build, causing James to step in and offer up some protection, and possibly igniting a spark in the process.