One of the terrific unsung series on TV, “Boardwalk Empire” (HBO, 9 p.m.) returns for its fourth season with all the qualities of a great show: perfectly toned period setting (which is now February, 1924), strong writing, expert direction and one of the best casts around, led by Steve Buscemi as the Atlantic City bootlegging kingpin.

As action begin, he’s settling up for that whole season of Gyp Rosetti, with a new cloud emerging — a brash talent agent clashing with Chalky White’s right hand man. Of the other characters we glimpse, the masked Richard Harrow returns for a visit home while doing a job. And new on the scene is a seemingly clueless FBI agent played by Brian Geraghty. Still to come this season, Jeffrey Wright as an unusually compelling big player from Harlem, Ron Livingston as a romantic interest of Gillian, and a venture into Florida where Patricia Arquette will pop up. And don’t worry Michael Shannon returns next week as G-man turned gangster muscle.

Sunday nights on PBS means all-British drama, more than ever, with “Masterpiece Mystery” (PBS, 9 p.m., check local listings) continuing with the “Silk” legal series, as a new standalone series begins, “Last Tango Halifax” (PBS, 8 p.m., check local listings, a romance between septuagenarians played by Anne Reid and Derek Jacobi. The main problem is their adult children are not keen on the idea.

“Sunday Night Football” begins in earnest with Giants at Cowboys (NBC, 8:20 p.m.). Carrie Underwood sings the new theme. Big deal.

Hope the remaining episodes of “Breaking Bad” (AMC, 9 p.m.) don’t end up being just a cat and mouse game between Jesse and Walt, as it started to be last week.

With the Operation Genoa story in the rear view mirror (until the lawsuits start), the cast of “The Newsroom” (HBO, 10 p.m.) must concentrate on the big story at hand: Election Night, 2012. Spoiler alert: We already know who won.

How the Midwest immediately reacted to 9/11 as it happened can be seen in the special “9-11: The Heartland Tapes” (Smithsonian Channel, 8 p.m.). The four hour “Inside 9/11” (National Geographic, 7 p.m.) takes up the whole of prime time. There’s 9/11 coverage on CNN all night too including a repeat of their documentary “The Flag” (CNN, 9 and 10:30 p.m.). The anniversary is Wednesday.

In the newly reduced “Big Brother” (CBS, 8 p.m.), with both Amanda and Elissa gone, new head of household makes more nominations for eviction.

Big Ang of “Mob Wives” runs her own Florida bistro in the series “Miami Monkey” (VH1, 10 p.m.).

A “Junior MasterChef” is set for this fall on Fox, but the Food Network gets a jump on them with the special “Rachael vs. Guy” Kids Cook-Off” (Food Network, 8 p.m.) in which each one mentors four kid cooks. They also get Michelle Obama to show up, just to ensure that they’re not making junk food.

Where’d Howard Kurtz wind up after leaving CNN? Hosting “MediaBuzz” (Fox News, 11 a.m.). Feel bad for him.

A couple of new things tonight on Lifetime Movie Network, “Killer Kids” (9 p.m.), which isn’t a movie at all, but a one hour series, and “I Killed My BFF” (10 p.m.).

The 41-film Alfred Hitchcock retrospective Sundays this month on Turner Classic Movies includes today with “Under Capricorn” (10 a.m.), “Stage Fright” (noon), “I Confess” (2 p.m.), “The Wrong Man” (4 p.m.), “Saboteur” (6 p.m.), “Foreign Correspondent” (8 p.m.), “North by Northwest” (10:15 p.m.) and “The Ring” (12:45 a.m.).

Pick your Bond: “Thunderball” (Encore, 8 p.m.) or “Die Another Day” (Showtime 2, 10 p.m.).

Sunday night baseball has Dodgers at Reds (ESPN, 8 p.m.).

Sunday Talk

ABC: White House Chief of Staff Denis McDonough, Sen. Ted cruz, Reps. Jaime Herrera Beutler and Adam Kinzinger. CBS: McDonough, Reps. Mike Rogers, Elijah Cummings and Justin Amash. NBC: McDonough, Reps. Peter King, Loretta Sanchez and Mike McCaul, Sen. Tom Udall. Newt Gingrich, David Axelrod. CNN: Reps. Marsha Blackburn, Jim McGovern, Buck McKeon, Barbara Lee, Gerry Connolly and Chris Coons. Fox News: McDonough, Sen. Rand Paul.