1) “The Flash” season-opener, 8 p.m., CW. Now for something really big: This show– which finished its seventh season in July – starts its eighth with a five-week epic. The world is in peril (again) and all of the superheroes – well, all the ones in CW’s universe – are needed. A villain named Despero arrives; The Flash assembles his friends. We quickly see Brandon Routh as The Atom (shown here with The Flash); also on the way are Batwoman, Green Arrow, Black Lightning, Sentinel, Damien Darkh and Reverse Flash.
2) “The Resident,” 8 p.m., Fox. Last week, it became clear that Conrad isn’t happy in his new life as a “concierge physician.” He loves working at the hospital … but that’s not easy when you’re widowed and raising a pre-schooler. Now he tries one day of hospital work, just as Devon leads a new set of interns and Austin has a book-signing. For what has become an excellent show, this is merely an OK episode, weighed down by some clunky moments involving one of the interns.
3) “Riverdale” season-opener, 9 p.m., CW. After last year’s COVID slowdown, the seasons blend. Six weeks ago, the fifth season ended with disasters: Separately, people burned the diner, burned the newspaper and ran Hiram (Veronica’s dad) out of town; the town was re-formed, with Veronica and Reggie starting a casino and Betty starting an FBI office. She also fell back in love with Archie … just before Hiram returned and set off a bomb. Now we see if they survived … and what disaster is next.
4) “La Brea,” 9 p.m. Tuesday, NBC. This has strained credibility wildly, what with people falling into a sinkhole and (apparently) into 10,000 BC. But in the final minutes tonight, there’s a twist so weird that the rest seems like a sober documentary. “La Brea” keeps holding our interest, despite a flaw that re-appears here: Characters become unrealistically overwrought, for the convenience of the plot.
5) “American Veteran” and “American Exile,” 9 and 10 p.m., PBS. First, the excellent “Veteran” concludes. J.R. Martinez – the actor and “Dancing With the Stars” champion who was severely wounded in Iraq – hosts an hour in which people take an overview of the military experience. Then comes a chilling hour, focusing on war veterans who face deportation.