Worth Watching: ‘Jeopardy!’ Teachers Tournament, Chilling ‘Chernobyl,’ Sundance’s ‘State of the Union’

A selective critical checklist of notable Monday TV:

Jeopardy! (Syndicated, check local listings): Most years, the classic quiz show’s annual Teachers Tournament is a cause for celebration — because who doesn’t love and appreciate teachers? They also happen to be good Jeopardy! players. But none of them are James Holzhauer, who’s breaking single-day earning records, and with more than 20 consecutive wins under his belt is second only to Ken Jennings in his remarkable, and remarkably addictive, run. James’ fans (and the occasional detractor) will just have to wait for the next two weeks to watch 15 accomplished educators battle it out for a $100,000 grand prize‑James sometimes wins that much in a single game — and a spot in the Tournament of Champions. (Mark your calendar: James is back in the champs’ seat May 20.)

Chernobyl (9/8c, HBO): Like a real-life disaster epic churning with the relentlessness of a horror movie, this grueling five-part docudrama would be terrifying if it were merely science fiction. The fact that it really happened — and for all of its devastation, could have been worse — makes this long slog of unrelieved misery even more chilling. The opening chapter depicts the grisly calamity of the 1986 nuclear accident in Ukraine, with those in charge staying in denial about the enormity of the explosion until it was almost too late to contain the damage. (It’s already too late for those on site, neighbors gathering outdoors to watch the blaze at night, and the first responders whose exposure to toxic radiation proves devastating.) Jared Harris is excellent as the scientist first brought in to assess the tragic and globe-threatening situation.

State of the Union (10/9c, SundanceTV): In what could be called “Scenes From a Failing Marriage,” this short-form dramedy unfolds in 10-minute chapters, each taking place in a London pub where estranged husband and wife Tom (Chris O’Dowd) and Louise (Rosamund Pike) meet before attending counseling sessions. With a script by Nick Hornby and direction by Stephen Frears, these terrific actors make the most of these vignettes, with humor, pain and grudging affection coloring their reflections on just went wrong to get to them to this point. SundanceTV will air individual episodes on a nightly basis, Monday to Friday, for the next two weeks. If you want to burn through the episodes more quickly — and who could blame you — back-to-back episodes will launch each day through Friday at 5 pm/4c on the Sundance Now streaming service, SundanceTV.com and the SundanceTV app.

Inside Monday TV: ABC is billing it as The Bachelorette Reunion: The Biggest Bachelorette Reunion in Bachelor History Ever! (8/7c), and you already know if this feels more like catnip or arsenic. With Hannah Brown starting her own Bachelorette journey in a week, Chris Harrison goes down memory lane with Trista, DeAnna, Jillian, Ali, Ashley, Emily, Desiree, Andi, Kaitlyn, JoJo, Rachel and Becca… There’s a chill in the air as National Geographic Channel’s Hostile Planet (8/7c) concludes with “Polar” survival stories set in the frigid Arctic and Antarctic regions, as polar bears hunt whales, penguins dodge leopard seals and a pack of Arctic wolves go after a pair of musk oxen… A supersized two-and-a-half hour series finale of Freeform’s fantastical saga Shadowhunters (8/7c) finds the demon hunters working to stop Clary’s (Katherine McNamara) vengeful brother, Jonathan (Luke Baines), and Alec (Matthew Daddario) moving heaven and earth for a happily-ever-after with warlock Magnus (Harry Shum Jr.)… Renewed for a third season, Fox’s medical melodrama The Resident (8/7c) closes out its second with Bell (Bruce Greenwood) thinking about selling the financially strapped Chastain Park hospital to a conglomerate. Ironic, given that the show airs on a network whose former studio was swallowed up by Disney.