1) “Chicago P.D.,” 10 p.m., NBC. Easily the best of NBC’s three Chicago shows, “P.D.” (shown here in a previous episode) offers a taut hour that spills into next week’s season-finale. Samantha Miller (Nicole Ari Parker) is a police reformer who joined the show this season; now her son needs help, in what seems like a quick case, then grows. One bit of inaction strains credibility; also, viewers will be disappointed that this is the rare “P.D.” episode that doesn’t wrap things up. Still, it’s a strong, solid hour that will bring them back next week.
2) “Chicago Med” and “Chicago Fire,” 8 and 9 p.m., NBC. No match for “P.D.,” these shows tend to have flat acting and scattered storytelling. “Med” returns to two stories – a psychiatrist with an obsessive patient and a drug trial that was compromised when a doctor gave some of the pills to her mother. “Fire” does have a couple of big romantic moments, one of them – mid-fire, no less – quite dramatic. But alongside that, it sticks Cruz into a situation written with sledge-hammer subtlety.
3) “The Masked Singer,” 8 p.m., Fox. A week from the finale, four singers remain, disguised as Black Swan, Piglet, Chameleon and Yeti. The ringers were ousted early and now some legitimate singers are being unmasked – Bobby Brown, Mark McGrath, Tyrese Gibson and more. Last week, it was Hanson, the brothers (now 40, 38 and 35) whose “MMMBop” was No. 1 in the U.S. and 13 other countries.
4) “The Conners” season-finale, 9 p.m., ABC. It’s been a good (if inconsistent) year for this show, deftly mixing comedy with bits of pandemic drama. Tonight, ABC says, there will be two marriage proposals; also, Jackie will capitalize on her awful “Jeopardy” appearance. The other ABC comedies also wrap their seasons: “The Goldbergs” (8 p.m., also with a proposal) and “Home Economics” (8:30, with siblings learning about Tom’s book) will be back next season; “Call Your Mother” (9:30) won’t.
5) “Life at the Waterhole,” 8 p.m., PBS. In a clever idea, a new water hole was dug in an African nature park, with cameras nearby. The opener of this three-week series spends too much time with people, but still has intriguing glimpses of everything from a huge lion to tiny birds. More non-fiction: At 9 p.m., PBS’ “Nova” has an excellent re-examination of the Hindenburg disaster. At 8, 10 and midnight, the Smithsonian Channel has “Cher and the Loneliest Elephant,” which is also on Paramount Plus.