S2, E3: When an attack is made on the President (guest star Lynda Carter) as hot-button, alien vs. human rights issues heat up in National City, Supergirl and the DEO are assigned to protect the President and bring in the responsible party. While Alex teams up with Detective Maggie Sawyer (Floriana Lima) to investigate the case, Kara searches for a recently escaped Mon-El (new series regular Chris Wood), who she fears may be the alien behind the assault.