“Back to You” (8:30 p.m., Fox): On “Back to You,” Kelly is having second

“Back to You” (8:30 p.m., Fox): On “Back to You,” Kelly is having second thoughts about informing Gracie that Chuck is her father. So she and Chuck go see a therapist to resolve their issues. Unfortunately, the session winds up bringing a lot of pent-up frustrations to the surface.

“Strange Days on Planet Earth” (9 p.m., PBS): Edward Norton says the way we treat our water is having a rippling effect.

“Law & Order” (10 p.m., NBC):The dramatically promising “K-Ville” didn’t last long on Fox last fall. It was done in by low ratings and the disruption of the writers strike. But its star has wasted no time bouncing back, right into TV’s longest-running drama. Anthony Anderson joins the cast of “Law & Order” as this NBC institution airs the first of five new episodes to complete its 18th season. And on the same episode veteran cast member Jesse L. Martin makes his final appearance after nine seasons as Detective Ed Green. Does good-cop Green really kill a notorious hustler who resurfaces inconveniently from his past? That’s how it appears to his partner, Detective Cyrus Lupo, when called to the crime scene. Then the case is turned over to internal affairs Detective Kevin Bernard, played by Anderson. The real question seems to be: What secrets has Green been keeping from his colleagues and from viewers all these years? Look for Bernard to fill the slot Green is about to vacate in the show’s six-character template. But only time will tell how Bernard gets along with Lupo (Jeremy Sisto, in his own freshman year on the series).Anderson, a gifted performer in both comedy and drama, has appeared in such films as “The Departed,” “Me, Myself & Irene” and “Transformers,” and was riveting as an LA gang leader on FX’s “The Shield.” Now he becomes the 25th actor (give or take) to be a “Law & Order” regular.