It’s almost the end: Roger Sterling receives a troubling phone call on the mid-season finale of "Mad Men." (Michael Yarish/AMC)

For those behind on Season 2, STARZ is airing the four most recent episodes of “Da Vinci’s Demons” (8 p.m.) back-to-back so loyal fans can catch up.

On “Orphan Black” (BBC America at 9), Sarah makes an unlikely ally who chooses to accompany her on her quest to find the origins of the clone experiment.

Geraldo Rivera revisits the June 1994 murders of Nicole Brown Simpson and Ronald Goldman and the subsequent trial of O.J. Simpson, with interviews with witness Kato Kaelin and lawyers Alan Dershowitz and Gloria Allred on “Geraldo Rivera: O.J. Simpson at 20” (Fox News at 10).

Sunday talk shows: “Platts Energy Week” (WUSA at 8 a.m.) interviews Federal Railroad Administration’s Joseph Szabo; “BioCentury This Week” (WUSA at 8:30) features Max Planck Institute for Evolutionary Anthropology’s Svante Paabo; “Fox News Sunday” (Fox at 9) hosts Sen. Kelly Ayotte (R-N.H.); “White House Chronicle” (WETA at 9) has Brown University’s Daniel Smith; “State of the Union” (CNN at 9) features Gov. Mike Pence (R-Ind.).

“Government Matters” (WJLA at 9:30) hosts Government Executive’s Frank Konkel; “This Week” (ABC at 10) features Army General Martin Dempsey; “Newsmakers” (C-SPAN at 10) talks to Sen. Bernard Sanders (I-Vt.); “Sunday Morning Futures With Maria Bartiromo” (Fox News Channel at 10) hosts TransCanada’s Russ Girling; “This Is America & the World” (WETA at 10 and WHUT at 6 p.m.) talks to Japan’s tourism commissioner, Shigeto Kubo; “Face the Nation” (CBS at 10:30) talks to Sen. Richard Blumenthal (D-Conn.).

On Sunday night, the two-part, two-hour documentary “Unsung Heroes: The Story of America’s Female Patriots” (MPT at 6 p.m.) highlights the heroism and bravery of women serving in the American military. from those who donned men’s clothes to fight in the Revolutionary War to Sgt. Leigh Ann Hester, who received the Silver Star for valor in combat for her actions in 2005 Iraq.

Starring Mark Ruffalo, Matt Bomer, Julia Roberts, Taylor Kitsch, Jonathan Groff, Jim Parsons and others, the Ryan Murphy-produced film “The Normal Heart” (HBO at 9) brings the groundbreaking Tony Award-winning play by the same name to life. The drama tells the story of the onset of the HIV-AIDS crisis in New York City in the early 1980s, taking an unflinching look at the nation’s sexual politics as gay activists and their allies in the medical community fight to expose the truth about the burgeoning epidemic to a city and nation in denial.

FINALE WATCH: Don gets a letter, Peggy seeks a new future and Roger receives a troubling phone call on the mid-season finale of “Mad Men” (AMC at 10).

Rachel Lubitz