1) “Supernatural” series finale, 9 p.m., CW, with preview at 8. For 15 seasons, two brothers(played by Jared Padalecki, shown here, and Jensen Ackles) have battled demons and intermittently saved the world. In the preview, Eric Kripke says he created the show with “the love of urban legends I’ve had my whole life.” Then he added more. The show, Misha Collins (who plays Castiel) says, has “the most epic mythology humanity can contrive.” We see that in the preview, ranging from angels to Lucifer, from a teen musical to a Scooby-Doo cartoon.
2) “A Million Little Things” season-opener, 10 p.m., ABC. The first two seasons took Eddie on a wild ride. He was having an affair with Delilah, until Jonathan (her husband, his close friend) committed suicide. He managed to re-assemble his marriage with Katrherine … then was struck by a hit-and-run driver. That’s where the season starts: Katherine leans on her friends, who have their own troubles. Asnd Delilah, seeing her kids thrive, wishes she could do the same.
3) “B Positive,” 8:30 p.m., CBS. The opening minutes are hilarious, which shouldn’t surprise us. Annaleigh Ashford is the best new TV comedy star in approximately forever. What is surprising, however, is this episode’s ability to turn subtly serious. This is, after all, the story of a guy who needs a kidney transplant to survive. The sobering part is tackled with understated warmth.
4) “Superstore,” 8 and 8:30 p.m., NBC. In the first new episode, Dina finally gets her chance to run the store. In the second, Mateo (who is undocumented) wants to make a good impression before his hearing. With that in mind, he holds a toy drive.
5) “Star Trek: Discovery,” 10 p.m., CBS. Two things that are always fun are temporal loops and a loopy Rainn Wilson. This hour has both. Loops – forever re-living the same time span – were around even before “Groundhog Day”;/ they get interesting when one person knows he’s in loop. This one is maneuvered by Harry Mudd, played with delightful glee by Wilson..