Monday's TV highlights: The CW's "Supergirl" on KTLA

Supergirl Absent for most of this season, Calista Flockhart returns, and her character's reappearance complicates the problem Supergirl (Melissa Benoist) is facing involving actions that the president (guest star Lynda Carter) wants taken against Rhea (guest star Teri Hatcher). Dancing With the Stars In this new episode of the unscripted competition, each judge gives a couple a specific challenge. Also, Cheryl Burke returns to the dance floor for a special performance, and Calum Scott performs. Gotham The secret weapon earmarked by the Court of Owls to demolish the city is found by Gordon (Ben McKenzie), while Bruce (David Mazouz) discovers something dangerous in the plan devised by Kathryn and Temple Shaman (guest stars Leslie Hendrix and Raymond J. Barry). Man With a Plan Don and Marcy's (Kevin Nealon, guest star Kali Rocha) joy over getting a visit from their new grandson leads Adam and Andi (Matt LeBlanc, Liza Snyder) to consider having another baby.