Kate Mara has no fear about tackling prickly, complex characters, so her titular role in the new limited series “A Teacher” (Hulu, streaming) is no different. It’s about a teacher and a high school student (Nick Robinson) who fulfill each other’s needs in an illicit affair. This story, created by Hannah Fidell and based on a 2013 film she made with the same name, may be more thoughtful than similar fare. But it still comes with the built-in creepiness of what is overall still a resoundingly bad idea. Three of the half hour  episodes drop today of the 10 total. 

A healthier relationship can be found in “Dash & Lily” (Netflix, streaming), based on the novel “Dash & Lily’s Book of Dares” explores a flirtation between two teens who write to each other in a bookstore journal around Christmastime in New York. Midori Francis and Austin Abrams star. 

The two-part documentary “The Cost of Winning” (HBO, 9 p.m.) looks at a Baltimore high school football team that was so good they were thrown out of their league.

“Country Strong 2020: Countdown to the CMA Awards” (ABC, 10 p.m.) is a kind of pre-show to Wednesday’s award show. 

“The Curse of Oak Island” (History, 9 p.m.) returns for its eighth season of trying to find the elusive treasure there.

Julianne Moore, Bill Hader and Kehinde Wiley look at their family histories on “Finding Your Roots with Henry Louis Gates Jr.” (PBS, 8 p.m., check local listings).