NCIS (7 p.m., Ch. 2): After months of tracking his target, Tony needs Gibbs to help him find answers.

Dancing With the Stars (7 and 8 p.m., Ch. 4): The contestants' first performances; the couple with the lowest score faces elimination.

The Biggest Loser (7 p.m., Ch. 5): The contestants are divided into teams and asked to choose one of three trainers .

History Detectives (7 p.m., Ch. 7): A man earns the Order of Leopold; suffragette pennant; WB cartoon cel.

Glee (7 p.m., Ch. 13): Mr. Schuester starts the school year by assigning the glee club kids a project to get them back on track

NCIS: Los Angeles (8 p.m., Ch. 2): The team searches for Hetty in Romania.

New Girl (8 p.m., Ch. 13): After a sudden breakup with her long-term boyfriend, Jess (Zooey Deschanel) moves in with three single guys.

Ringer (8 p.m., The CW): Bridget's past starts to catch up with her as she tries to learn more about Siobhan's life.

Raising Hope (8:30 p.m., Ch. 13): Jimmy learns he was a musical prodigy until an accident ruined his talent.

Unforgettable (9 p.m., Ch. 2): A murder reunites former detective Carrie Wells with her ex-boyfriend and colleague.

Body of Proof (9 p.m., Ch. 4): The investigation into a fatal car crash reveals the seedy underbelly of a perfect-looking neighborhood.

Parenthood (9 p.m., Ch. 5): Kristina worries about Max attending a mainstream public school.