Best Bets

7 p.m. on PBS Extra Life: A Short History of Living Longer

Hosted by science writer Steven Johnson and historian David Olusoga, this absorbing new four-part series examines some of the medical innovations that were developed to conquer some of the world’s deadliest diseases — smallpox, cholera and the Spanish flu, among others — and explores how scientists, doctors and activists used those breakthroughs to launch a public health revolution. In some parts of the world, life expectancy doubled over the course of less than a century as perspectives on illness changed, paving the way for modern medicine.

7 p.m. on CBS NCIS

A case literally hits close to home for Gibbs (Mark Harmon) when his team tracks a stolen laptop computer to the uncle of Phineas (guest star Jack Fisher), a young boy who used to be one of Gibbs’ neighbors, in a new episode called “Unseen Improvements.” Other guest stars include John Bobek, Anahi Bustillos, Karri Turner and Philip Shahbaz; Sean Murray, Emily Wickersham and Maria Bello also star.

8 p.m. on ABC black-ish

After one of the secrets that he shares with Pops (Laurence Fishburne) is revealed to Ruby (Jenifer Lewis), Dre (Anthony Anderson) has the revelation that his relationships with each parent have shifted since they got married, leaving him uncertain to know which of them he should confide in, in the new episode “Snitches Get Boundaries.” Meanwhile Bow (Tracee Ellis Ross) surprises the twins (Miles Brown, Marsai Martin) with a new car. Marcus Scribner also stars.

8 p.m. on CW Supergirl

Series regular David Harewood directed the new episode “Fear Knot,” which follows the intrepid Super Friends as they venture into the Phantom Zone in a life-or-death gambit to rescue Supergirl (Melissa Benoist) and bring her back home to the present. As they search for their friend, each member of the team is tormented by visions of their worst nightmare. Chyler Leigh, Nicole Maines and Jesse Rath also star.

8 p.m. on TLC Little People, Big World

There’s nothing “little” about this show’s success, as the Roloffs prove by returning for their 22nd season, which finds them hunkered down during the COVID-19 pandemic. Zach ponders a future in which he co-owns and runs the family farm with his dad, Matt, but he’s unsure what that partnership might involve. Meanwhile, Matt’s ex-wife, Amy, has moved out and started planning her wedding to fiancé Chris. Alas, it soon becomes obvious that the couple has different visions of what their big day should be.

8 p.m. on HBO The Crime of the Century

The conclusion to filmmaker Alex Gibney’s two-part examination at shady dealings behind the opioid epidemic delves into the mass marketing of fentanyl, where once again there were strong connections between drug manufacturers and government policy. Even as the silent opioid epidemic was killing 40 Americans every day, Insys Therapeutics, the manufacturer of fentanyl, continued to bribe doctors to over-prescribe their drug. Eyebrow-raising videos from sales retreats, as well as promotional materials, point to a nearly complete disregard for widespread and nefarious corporate practices.

8:01 p.m. on FOX Prodigal Son

With a serial killer on the run, Malcolm (Tom Payne) becomes so driven to find and capture the police team’s quarry that U.S. Marshal Emily Ruiz (guest star April Hernandez-Castillo) feels compelled to boot him off the case in the new episode “Sun and Fun.” Unfortunately for her, the obsessed Malcolm isn’t inclined to back off. The guest cast also includes Catherine Zeta-Jones and John Cullum; Michael Sheen and Bellamy Young also star.

8:30 p.m. on ABC mixed-ish

When Paul (Mark-Paul Gosselaar) seeks to become closer to sister-in-law Denise (Christina Anthony), he exploits his white privilege to help her out with her errands in the new episode “Walk This Way.” Meanwhile, Rainbow (Arica Himmel) and her siblings (Ethan Childress, Mykal-Michelle Harris) pick up some questionable sales tactics while hustling chocolate bars for a school fundraiser. Tika Sumpter also stars.

9:03 p.m. on HIST America’s Book of Secrets

Host Lance Reddick returns for Season 4 of this docuseries, which purports to reveal the truth behind some of history’s most shocking headlines. The season premiere, “The Secret Space Program” dives into a 2002 story about a man named Gary McKinnon, who claimed he had uncovered evidence of a secret military space program, nearly 20 years before the Trump administration announced its Space Force program. The episode considers whether the United States may have a covert presence in space of which the public is unaware.