Tomorrow night's Supergirl shows us CADMUS using the alien registration list to kidnap aliens and they're using what appear to be National City police officers to help round them up. That is until Alex Danvers (Chyler Leigh) shows up in the scene. Alex is determined to stop CADMUS and Lillian Luthor after what happened with her father, Jeremiah, last week.
Supergirl airs Mondays at 8 PM on the CW.