Armek, a White Martian, descends on National City intent on taking M’gann back to Mars to face her punishment as a traitor. Hank and Supergirl determine the best way to keep M’gann safe is to bring her to the DEO. However, when it is revealed that Armek shape-shifted into M’gann and is now loose in the building, the team realize he could be disguised as any one of them.
Elenco: Melissa Benoist , Chyler Leigh , David Harewood , Mehcad Brooks , Jeremy Jordan , Katie McGrath , Chris Wood , Jesse Rath , Nicole Maines , Odette Annable , Floriana Lima , Calista Flockhart , Andrea Brooks , Azie Tesfai , Julie Gonzalo , Staz Nair .