1) Presidential debate, 9-11 p.m. ET (6-8 p.m. PT), ABC, CBS. NBC, Fox, PBS and news channels. Sure there are alternatives (including the “Despicable Me” movies, shown here), that we’ll mention in a minute. But this is what counts — a high-stakes collision between Donald Trump and Joe Biden, with Chris Wallace of Fox News moderating. others will be Oct. 15 and 22 … plus an Oct. 7 vice-presidential debate with Mike Pence and Kamala Harris.
2) “The Weakest Link” debut or “Love Island,” 8 p.m., NBC or CBS. Prior to the debate – or after it, on the West Coast – TV will revert to its natural state, which is reality and games and such. This is the opening night of the rebooted “Link” game, now with Jane Lunch hosting. And this was originally announced as the final night of “Love Island”; now, instead, the “Love” ends Wednesday.
3) “Cosmos: Possible Worlds,” 8 p.m., Fox. Last week, Neil deGrasse Tyson focused on other worlds that might sustain life. Now here’s a down-to-Earth question: Just how did life start here? He ponders a blood-red sea in early Earth and profiles a scientist who defied Nazi tormentors.
4) “Tell Me a Story” finale, 9 p.m., CW. Originally on CBS All Access, this began with great promise – three tense stories, with lots of good actors and one great one (James Wolk, as a guy avenging his fiancee’s death). The problem? The stories have a certain sameness – lots of hostages, lots of fights with careless captors followed by third-party intervention. Tonight uses too much coincidence, but still manages to have some powerful moments. A second season starts in two weeks.
5) Movies, cable. On debate night, cable brings out the crowdpleasers. There’s animated fun from the “Despicable Me” films, at 6:30 (2010) and 8:30 p.m. (2013) on Freeform. At 8 p.m., try “Gladiator” (2000) on AMC, “The Martian” (2015) on FX or the smart, true-life “Just Mercy” (2019) on HBO.