When Senator Patrick Kiley seeks Gibbs' help to solve the murder of a young Naval officer, the NCIS team find themselves pushed inside the world of Washington politics.

Mrs. Kingston puts Jenn in an impossible situation when a tragedy occurs, and Cassie is less than pleased with Sage's new home.

As Silver's "half birthday" approaches, she decides to spend a spooky evening watching movies with her friends at the famous Hollywood Forever Cemetery. Harry's past returns to haunt him when Tracy reveals she is searching for their son. Annie and Ethan are paired up for an assignment, which deepens their connection after the two take care of a baby. Naomi confronts Adrianna as her drug addiction spirals out of control. Meanwhile, Ryan mourns Kelly's unexpected departure.

The results for week 3 of competition are revealed.

Part 1 of a 2 part episode finds one contestant being rewarded with a trip home for a visit, as the others are set to spend 24 hours with a personal trainer. Meanwhile, the teams are given an endurance challenge, in which one team is chastised for slacking off.

An investigative look in Alaska where the scientists delve 60 feet into the permafrost, to examine how dinosaurs handled the Arctic climate over 65 million years earlier. Included is a look at the dinosaur's diet, and reasons on why they may have become extinct.

It's the ZBZ Formal and Casey and Max decide to go together. At the event, Ashleigh and Rusty bond. Also, Rebecca decides to skip the event claiming she needs a break from sorority events.

Mike heads to San Diego to get dirty with the tar rigging crew of the Star of India, the oldest active merchant ship in the world. Then, Mike takes a look back at some of the dirty tools he's used that make civilized life possible for the rest of us.

Laurel gives Megan the task of chaperoning the twins' pool party, thus forcing her to cancel plans for a spa weekend with Jacob. Meanwhile, Charlie confesses to Marco that he is in love with Megan, and Megan is convinced by Rose to invite Lily to the pool party.

Vic sets into motion plans to end the gang threat as his relationship with Cassidy deteriorates; Dutch and Billings investigate a possible sleepwalking murderer.

William rescues a team member, while the others go undercover at a sorority house to get information about a drug dealer.

Monica stops by General Hospital; Anna and Robert discuss their past; The hospital is in danger thanks to Patrick; Eric and Kyle's relationship grows.

Segments:

-Palin attacks Obama (Six Degrees of Desperation)

-Senior Polling Analyst John Oliver

-Lewis Black in Back in Black looks at campaign attack ads



Sarah Vowell talks about her new book The Wordy Shipmates.

Tonight Stephen welcomes the owner of political website fivethirtyeight.com, Nate Silver.

Harry acts as mentor to Holly Farr, a young and eager medical student, who charms him into involving her in his latest case - the post-mortem of a woman found dumped on the side of the road with her face skilfully removed.

Nikki is called upon to reconstruct the victim's face, and the team cannot fathom why it would have been removed in such a careful manner until Holly discovers a connection with a dangerous Russian criminal.