'ONCE UPON A TIME': Mary Margaret and David celebrate the naming of their son at a coronation in Granny's Diner in the Season 3 finale. (Dean Buscher/ABC)

Starring Sonya Walger and Ben Bass, “The Good Sister” (Lifetime at 8 p.m.) melodramatically tells the story of Jack and Kate, a struggling couple until Kate gets a letter from a long lost twin sister named Linda. All is well until Jack is suddenly drawn to Linda who has a set of dangerous, cruel ulterior motives.

RETURNING SHOW: The UK’s more streamlined answer to “The Walking Dead,” “In the Flesh” (BBC America at 10), returns for Season 2 with Kieren not as safe as he thinks he is in Roarton.

Charlize Theron plays host to “SNL” (NBC at 11:30), with the Black Keys as musical guest.

Sunday talk shows: “Platts Energy Week” (WUSA at 8 a.m.) interviews Max Planck Institute for Evolutionary Anthropology’s Svante Paabo; “BioCentury This Week” (WUSA at 8:30) features Statoil’s Helge Lund; “Fox News Sunday” (Fox at 9) hosts the Malala Fund’s Shiza Shahid; “White House Chronicle” (WETA at 9) has author Paul Dickson; “State of the Union” (CNN at 9) features former Sen. Rick Santorum (R-Pa.).

“This Week” (ABC at 10) features Secretary of Defense Chuck Hagel; “Newsmakers” (C-SPAN at 10) talks to Rep. Hal Rogers (R-Ky.); “Sunday Morning Futures With Maria Bartiromo” (Fox News Channel at 10) hosts House Speaker John Boehner (R-Ohio); “This Is America & the World” (WETA at 10 a.m. and WHUT at 6 p.m.) talks to experts on modern Japan; “Face the Nation” (CBS at 10:30 a.m.) talks to Rep. Mike Rogers (R-Mich.).

FINALE WATCH: Sunday night, “Once Upon a Time” (ABC at 8) Season 3 concludes with the naming of David and Mary Margaret’s new son and a stressful experiment in Zelena’s time portal.

Stannis and Davos set sail on “Game of Thrones” (HBO at 9).

In an attempt to make one of cinema’s most disturbing stories TV-friendly, “Rosemary’s Baby” (NBC at 9) comes to the modern day where the residents of a Paris mansion are a little too friendly and much too evil. Stars Zoe Saldana. Part II airs Thursday, May 15.

SERIES PREMIERE: Josh Hartnett takes on the role of a charming American who finds himself trapped in the darkest corners of Victorian London on the new drama “Penny Dreadful” (Showtime at 10), while Eva Green plays a seductive and formidable beauty full of secrets and danger.

Don gets a visitor from his past and Peggy comes to Ginsberg’s aid on “Mad Men” (AMC at 10).

Rachel Lubitz