Supergirl is determined to keep everyone safe from Lex and Nyxly so she doubles down on patrol, especially as Alex and Kelly's bachelorette party is coming up. Alex is torn between duty and finally allowing herself the time to enjoy her new family. Brainy receives heartbreaking news, and William clashes with Andrea over her recent coverage of Lex.

In the epic series finale, Supergirl is joined by familiar faces from the past to help her stop Lex and Nyxly for good. Meanwhile, Alex and Kelly prepare to walk down the aisle.