1) “Quantum Leap” return,10 p.m., NBC. “Quantum” leaped from a fairly good first season to an excellent second. Alongside its time-trekking, it now has Ben’s personal pain, after he vanished into a time-twisted fog, His ex-fiancee has a new guy who plans to propose. Also, Ben keeps bumping across Hannah, a physicist he loves. This episode (he’s a bounty-hunter, shown here) brings much of that together.
2) “Finding Your Roots,” 8 p.m. Tuesday, PBS. Growing up in Dallas, comedian Iliza Shlesinger was partly separated from her Jewish roots. Now she learns of relatives who escaped the Holocaust and those who didn’t. On the lighter side, actor Bob Odenkirk finds a surprise (and a royal link). It’s a strong hour, mixing joy and despair.
3) “Frontline,” 9-11:30 p.m., PBS. This documentary series is usually an hour, occasionally a bit longer. Now, however, it sprawls to two-and-a-half hours, to probe the charges against Donald Trump relating to Jan. 6.
4) “Extended Family,” 8:30 p.m., NBC. The kids learn that their mom’s celebrity boyfriend has lot of special privileges. But is that a good thing? Their dad (Jon Cryer) doesn’t think so. The episode sometimes goes off-track, with people veering wildly out of character. But mostly, like all Cryer comedies, it’s kind of fun.
5) “La Brea,” 9 p.m., NBC. With only two episodes left after tonight, this seems to be in no hurry to resolve anything. Most people are in the sinkhole world that’s sort of like 10,000 BC … one is back in the pre-sinkhole life of 2021 … some are in both. Also, a fire rages and two women offer new solutions and/or problems. Somehow, this is all going to be settled on Feb. 13.