6 p.m. CNN CNN DEMOCRATIC DEBATE

From the campus of Otterbein University in Westerville, Ohio, the dozen qualifying candidates for the 2020 Democratic presidential nomination gather for their party’s fourth sanctioned primary debate. Moderators for the three-hour broadcast are CNN anchors Anderson Cooper and Erin Burnett, along with New York Times national editor Marc Lacey. Topics have not been announced in advance, but among them the current U.S. House of Representatives impeachment investigation of President Donald J. Trump seems likely to loom large.

8 p.m. SYFY USA TREADSTONE

Sleeper agents around the world are awakened to undertake the covert missions for which they were programmed in this sleek new spy drama from some of the producers on the “Bourne” movie franchise. In fact, this series is set in the world of the same secretive CIA initiative where super-spy Jason Bourne started, although while that character is mentioned, he never appears here. Jeremy Irvine (“War Horse”), Brian J. Smith (“Sense8”), Omar Metwally (“The Affair”) and Michelle Forbes (“The Killing”) star.

9 p.m. PARMT BATTLE OF THE FITTEST COUPLES

Ex-Bachelorette JoJo Fletcher and former NFL quarterback Jordan Rodgers, a real-life couple themselves, host this new reality competition series, in which 12 couples from around the United States compete in a series of grueling physical challenges for the chance to win $100,000 and the title of Fittest Couple. Hometowns represented include Los Angeles and Sacramento, Calif.; Tampa, Fort Lauderdale, Casselberry and Windermere, Fla.; Maui and Pahoa, Hawaii; Mechanicsburg, Pa.; Dalton, Ga., Charlotte, N.C., and Columbus, Ohio.