An arrest is made of the cult leader on the season finale tonight of the fascinating documentary series “The Vow” (HBO, 10 p.m.). But it was announced this week that second season is coming that will presumably cover what? The trial?

At the same time, one of the prominent and elusive cult victims from the series, India Odenberg, suddenly pops up to star in her own premium cable series on the subject, “Seduced: Inside the NXIVM Cult” (Starz, 9 p.m.). Maybe that’s why she didn’t call back her mother,  the former “Dynasty” star Catherine Oxenberg, in “The Vow” — she was dealing with her own camera crews. But what are we to make of so much documentary interest in NXIVM? It’s almost like … a cult! 

Daveed Diggs makes his debut as Frederick Douglass on “The Good Lord Bird” (Showtime, 9 p.m.). 

In the first season finale of “Lovecraft Country” (HBO, 9 p.m.), the origins of the Book of Names are used to cast a spell at Ardham. It follows a showing of Jordan Peele’s “Us” (HBO, 6:51 p.m.). 

Leslie Jones hosts a revival of “Supermarket Sweep” (ABC, 8 p.m.), not that grocery shopping seems like such a good game right now. It accompanies new seasons of “Who Wants to Be a Millionaire” (ABC, 9 p.m.) with Jimmy Kimmel, and “Card Sharks” (ABC, 10 p.m.).

Dawn French returns to public TV as a gossipy gift shop owner who must now make amends on “The Trouble with Maggie Cole” (PBS, 8 p.m., check local listings).