“The Walking Dead” – The monster hit returns for its third season and those gruesome ghouls are still in attack mode. Rick Grimes (Andrew Lincoln), now hardened and weary, continues to seek refuge with his fellow survivors in a desolate world, but the struggle to survive has never been more perilous. Season 3 also introduces new characters, including the maniacal Governor (David Morrissey) and the sword-wielding Michonne (Danai Gurira). 9 p.m. Sunday, AMC.
ToDAY: Ever wonder what Scott Baio is up to? Wonder no more. The “Happy Days” star returns to prime time in “See Dad Run,” a comedy in which he plays a former TV dad adjusting to actual fatherhood. 8 p.m., Nickelodeon.
MONDAY: Turns out that Steve McGarrett’s (Alex O’Loughlin) mother (Christine Lahti) isn’t going away quietly on “Hawaii Five-0.” 10 p.m., CBS.
TUESDAY: It’s Round 2 of the presidential debates as Barack Obama and Mitt Romney square off in a town-hall format. 6 p.m., broadcast networks and cable news channels.
TUESDAY: “Emily Owens, M.D.” is basically “Grey’s Anatomy”-lite. Mamie Gummer stars in the title role as a love-starved young doctor. 9 p.m., The CW.
TUESDAY: “The Men Who Built America” is a series that explores how five powerful men – Cornelius Vanderbilt, John D. Rockefeller, Andrew Carnegie, J.P. Morgan and Henry Ford – transformed the country into a global superpower. 9 p.m., History Channel.
WEDNESDAY: Mama drama on “Suburgatory”? In the Season 2 opener, Tessa (Jane Levy) begins to express an interest in her mom, who abandoned her when she was a baby. 9:31 p.m., ABC.
WEDNESDAY: Brace yourself for another twisted, crazy and scary ride. “American Horror Story: Asylum” returns with an entirely different saga set inside a New England facility for the criminally insane. 10 p.m., FX.
THURSDAY: “Ethel” is a compelling profile of Ethel Kennedy that spans the life she shared with husband Robert Kennedy and the years following his death. 9 p.m., HBO.
FRIDAY: Ding-dong, Percy is dead, but “Nikita” is still roiling with danger. Now in charge of Division, Nikita and Michael (Maggie Q, Shane West) are out to capture a group of rogue agents called the Dirty 30. 9 p.m., The CW.
SATURDAY: “The Girl” is a new film that delves into Alfred Hitchcock’s dark side. It follows the famed director (Toby Jones) as he develops a creepy obsession for Tippi Hedren (Sienna Miller), his leading lady in “The Birds” and “Marnie.” 9 p.m., HBO.