“The Closer” (8 p.m., TNT): “The Closer” returns for a special two-hour

“The Closer” (8 p.m., TNT): “The Closer” returns for a special two-hour holiday episode that has Brenda and Fritz investigating the killings of two armored-car guards. Poor Brenda finds herself juggling her parents’ desire to spend Christmas as a family with her mission to get a murderer behind bars. The show precedes a new episode of “Saving Grace.”

“Heroes” (9 p.m., NBC): “Volume Two” of “Heroes” comes to an explosive finish with an episode that has Peter’s long-anticipated reunion with Nathan turning violent when the brothers, Matt and Hiro all wind up clashing, thanks to Adam and his pursuit of the deadly Shanti Virus.

“Intervention” (9 p.m., A&E): Emily, a 26-year-old identical twin, grew up in a highly competitive household. Despite winning numerous academic and athletic honors — including a full college scholarship — she always felt that she was never good enough. In college, she turned to dieting in an attempt to regain control of her life. Now, seven years later, the 5-foot-9 former star athlete weighs 85 pounds and is slowly starving herself to death. Emily’s story begins a new season of “Intervention,” the A&E documentary series that profiles people struggling with addictions. Each episode ends with a surprise intervention staged by the addict’s family and friends, and conducted by one of the series’ resident specialists.

“Saving Grace” (10 p.m., TNT): Holly Hunter is back with her guardian angel, just in time for Christmas.