Monday's TV Highlights: “The Big C” on Showtime
How I Met Your Mother: Barney (Neil Patrick Harris) finds a copy of the Canadian kids show featuring Robin (Cobie Smulders) and the gang learns even more about her past as a performer than expected, in this new episode (8 p.m. CBS).
Chuck: Worried that his most recent setback is coming between him and Sarah (Yvonne Strahovski), Chuck (Zachary Levi) tries to prove himself by going on a hazardous mission. Summer Glau guest stars in this new episode (8 p.m. NBC).
House: After a 200-year-old medicine jar from an offshore shipwreck shatters in a teenager's palm, she is admitted to the hospital with symptoms closely linked to smallpox. Hugh Laurie and Amber Tamblyn star with guest star Dylan Baker (8 p.m. Fox).
Castle: When a prominent astrophysicist is found dead of explosive decompression in her car, Castle (Nathan Fillion) theorizes her death was the result of an alien abduction. Lance Henriksen guest stars as an expert in alien abductions and Lyle Lovett appears as a shadowy government agent who is suspiciously eager to close down the investigation in this new episode (10 p.m. ABC).
Weeds: Nancy (Mary-Louise Parker) faces difficult choices as she and her family head for the airport to flee the country. Justin Kirk, Alexander Gould, Richard Dreyfuss and Hunter Parrish also star in the season finale (10 p.m. Showtime).
Town Hall Event: Immigration: Lawrence O'Donnell and Maria Teresa Kumar host this live event from the University of San Diego (7 and 11 p.m. MSNBC).
Valentine's Day: A diverse group of Los Angeles residents wends its way through love, romance and heartbreak in this 2010 TV movie (7:50 p.m. Cinemax).
One Angry Juror: Jessica Capshaw and Jeremy Ratchford star in this 2010 courtroom drama (9 p.m. Lifetime).
Hockey: The Kings visit the San Jose Sharks (7:30 p.m. FSN).
Pro basketball: The New Jersey Nets visit the Clippers (7:30 p.m. FS Prime).
Photo: Ken Regan / Showtime