Supergirl Teri Hatcher (“Lois & Clark: The New Adventures of Superman”) guest stars as a new villain whose arrival in National City puts Supergirl (Melissa Benoist) on high alert. Floriana Lima also guest stars in this new episode. 8 p.m. KTLA
Dancing With the Stars Olympic gold medalist Simone Biles; figure skater Nancy Kerrigan; Heather Morris (“Glee”); Charo and World Series champ David Ross (the show’s first professional baseball player) are among the celebrity contestants as this new season of the unscripted competition begins. 8 p.m. ABC
24: Legacy Donovan (Jimmy Smits) begins to question...