Sherlock (10pm, UNC-TV) - The third season of the outstanding Masterpiece Mystery series opens two years after the events of last season’s shocking finale, in which Holmes apparently died. Watson has gotten on with his life, but can’t help but to wish his old pal was still with him. And that wish may just come true when London is threatened with a terrorist attack.
Also on tonight . . .
Downton Abbey (9pm, UNC-TV) - In the third episode, Mary, Edith, Tom and Anna each struggle with a dilemma. Also, Gillingham makes clear his intentions to Mary, Edith endangers her reputation and Anna keeps her distance from Bates. Don’t forget that each week, the previous week’s episode airs prior to the new one.
True Detective (9pm, HBO) - Pressure to land a suspect in the Lange murder brings a warning from Quesada that Hart and Cohle might be replaced by a new task force, but they lobby for extra time to investigate a rural brothel and a burned-out church.
Girls (10pm, HBO) - Hannah turns 25 at a wild party thrown by Marnie and her parents at a local bar, but the festivities are marred by an unexpected visit from Adam’s emotionally disturbed sister and Ray’s clash with Hannah’s editor over the soundtrack.
Looking (10:30pm, HBO) - In the premiere of this new dramedy about a trio of gay men in San Francisco, Patrick deals with news of his ex’s engagement; Augustin prepares to move in with his boyfriend; and Dom mulls reconnecting with an old flame.
Episodes (10:30pm, Showtime) - Matt continues to fight for custody of his kids, but getting a DUI with them in the car complicates the situation. Also, Carole falls under the spell of her charismatic new boss.
The Following (10:30pm, Fox) - Following the Seahawks-49ers football game, catch a Season 2 preview in which a murderous rampage takes place on the one-year anniversary of Joe Carroll’s death.