Monday’s TV Highlights: Tom Bergeron gust stars on ‘Castle’

A freaked-out Lily (Alyson Hannigan) wants to get a gun after Marshall (Jason Segel) is mugged. Josh Radnor, Neil Patrick Harris and Cobie Smulders also star in this new episode (8 p.m. CBS).

Life Unexpected: Cate’s (Shiri Appleby) approaching wedding forces her to confront her feelings for Ryan and Baze (Kerr Smith, Kristoffer Polaha) in the season finale (8 p.m. KTLA).

Animal Cops Houston: The team races to save four baby goats attacked by dogs in this new episode (8 p.m. Animal Planet).

Gossip Girl: Dorota (Zuzanna Szadkowski) asks Chuck and Blair (Ed Westwick, Leighton Meester) to be a part of her wedding, and Serena (Blake Lively) secretly meets with Carter (Sebastian Stan) after lying to Nate (Chace Crawford) in this new episode (9 p.m. KTLA).

24: President Taylor (Cherry Jones) turns to former President Logan (Gregory Itzin) to resuscitate the peace agreement, and Chloe (Mary Lynn Rajskub) is tasked with new responsibilities in this new episode (9 p.m. Fox).

Tough Love Couples: Steve and Joann counsel couples in crisis in this new series (9 p.m. VH1).

The Big Bang Theory: Sheldon (Jim Parsons) faces off once again with his wily nemesis -- guest star Wil Wheaton as himself -- in this new episode (9:30 p.m. CBS).

Nurse Jackie: Jackie dispenses illegal marijuana to a suffering patient (10 p.m. Showtime).


Among the Righteous: Lost Stories From the Holocaust in Arab Lands: In the wake of 9/11, Rob Satloff, head of a Washington policy center, throws himself into what becomes an eight-year search for Arab heroes and the fate of the half-million Jews of the Arab lands of North Africa under Nazi, Vichy and Fascist rule in this new special (10 p.m. KCET).


Baseball: The Milwaukee Brewers visit the Chicago Cubs (11 a.m. WGN A).

Basketball: The Dallas Mavericks visit the Clippers (7:30 p.m. FS Prime).