Elsewhere on TV ...
House (7 p.m., Fox/Ch. 13): An Alzheimer's patient who's in a drug trial is having violent outbursts.
Gossip Girl (7 p.m., CW/Ch. 30): Blair's bachelorette party turns into an event to remember.
The Layover (7 and 10 p.m., Travel): In the season finale, Tony spends time in Los Angeles.
Being Human (7 and 9 p.m., Syfy): Sally discovers she has more ghostly powers.
Republican presidential debate (8 p.m., NBC/Ch. 5): From Tampa, Fla. (Tape-delayed)
Hart of Dixie (8 p.m., CW/Ch. 30): Zoe learns she is a legacy to the Bluebell Belles.
Lost Girl (8 and 10 p.m., Syfy): Bo and Kenzi are visited by a Woodland Faye.
Castle (9:01 p.m., ABC/Ch. 4): A famous dog trainer is murdered.
Pretty Little Liars (9 and 11 p.m., ABC Family): The girls try to keep their loved ones safe.
The Lying Game (11 p.m., ABC Family): Emma is on the outside looking in at the country club ball.