A petty officer's recruitment session at a college fair comes to a fatal end, prompting the NCIS team, accompanied by Dr. Mallard's predecessor, to solve his murder.

Eric confesses that he is dating Lux while Baze comes to terms with the fact that his father cheated on his mother with Emma prior to their relationship.

While Internal Affairs officer Rachel Jacobs investigates reports of a rogue cop, Jim risks revealing himself as the prime suspect when the police station is overrun by a group of thugs, and he is the only hope of survival. Meanwhile, while trying to nurse an ailing Joshua back to health at the lab, Katie and Stephanie run into Human Resources VP Victoria Morrow and begin to suspect that she isn't who she says she is.

The 'unknown trainers' are finally revealed, and both will share their personal stories that led them to 'The Biggest Loser.' Their contestants, 'the unknowns,' confront one player they feel isn't working hard enough, and later, 'the unknowns' and the ranch contestants square off for a pop challenge. The winning player from each group will get a delicious healthy dinner prepared by Chef Curtis Stone, and compete for a coveted 2 lb. advantage at this week's weigh-in. Later, Dr. Huizenga gives 'the unknowns' startling news about their health, and one player is surprised to learn they have the highest percentage of body fat in the group. Meanwhile, trainers Bob Harper and Jillian Michaels single out a few of their contestants to find out what really led to their weight gain, and then the ranch contestants meet host Alison Sweeney for a water-carrying challenge that will give the winner the sole vote at this week's elimination. Later, a surprising weigh-in -- which results in shocking numbers for one team -- disappoints the trainers in a big way, leading to the elimination of one player they feel isn't ready to go home.

Malik's trouble continues and he gets himself arrested while driving drunk in the middle of the night and it jeopardizes his career. Melanie becomes overwhelmed while hosting a charity event, and Jazz, a former groupie, gives Melanie a little dose of reality.

Alex and her team have to spy on a right-wing terrorist group. But surveillance becomes difficult when their only vantage point is the nursing home where Alex's cranky grandmother lives.

A customer claims that he was overcharged for a watch. Ashley becomes irate with Les and Seth over their undermining of her authority. Les buys an elephant skull and porta-potty. Les has to take over a deal when Ashley offers too much money.

Mike goes to great heights to install a metal power pole in Wyoming. Later Mike puts on some pink scrubs and goes to work for the Hair Fairies in San Francisco to learn about how to remove lice from hair.

The NCIS team sets out to find the individual responsible for stealing a classified Pentagon document before the file's decryption code is cracked by the wrong party.

Unaware of the affair between Emma and his father, Baze considers buying a house and planning a future with Emma. Lux makes plans for a romantic dinner with Eric when she feels like he's pulling away from her, but she is shocked when Cate and Baze show up.

Team One try to talk down a delusional man who is holding a restaurant full of people hostage, including Jules and her paramedic boyfriend Steve.

Officer Ben Sherman seeks revenge after the man who raped his mother is released from prison. Detectives Adams and Ochoa deal with issues over a chainsaw, as Sammy Bryant deals with Tammi's betrayal.

Tosh gives aspiring thespian Brian Atene another shot at greatness. Daniel seeks out his own homeless man with a golden voice.

When Will fears his client is not getting a fair trial because the judge is biased toward him, the law firm hires a jury consultant, who claims to predict a case's outcome by reading people's expressions. Meanwhile, Will uncovers information about Bond's intent for the firm.

Kristina and Adam catch Haddie sneaking around with Alex and forbid her from seeing him anymore. Sarah faces a new challenge when Drew tells her he needs to sell five hundred dollars worth of wrapping paper. Meanwhile, Crosby and Jasmine have to deal with Jabbar's bad case of stage fright right before the school play.

Erica learns her partner, Malik, is a Visitor and must fight for her life - literally - to stop Anna from finding out she's Fifth Column.
Meanwhile, Anna learns that Malik is missing and orders Ryan to find her, while Lisa realizes her body is beginning to change, causing her to become more and more like her mother.

When Peter is suspended by the FBI for a crime he didn't commit, he is forced to run a sting with Neal and the gang to catch Mozzie's shooter, and clear his name.

When Leary is threatened with criminal charges, he must do the bidding of bookmaker Hal Brennan to make them go away. Lights is also being coy with his suspicious wife Theresa, and Mike Fumosa, a pesky reporter-both having heard rumors that he will return to the ring to fight Reynolds. Meanwhile, his daughter Daniella finds out about her father's diagnosis and confronts him.

Neil deGrasse Tyson

Conan welcomes actress Jennifer Garner who will be introducing The Kid's Cooking Academy along with Save the Children and Frigidaire, stand-up comedian Gabriel Iglesias will be performing and chatting and musical guests Social Distortion.

Cornel West

Actress Betty White; reality TV stars Kim and Kourtney Kardashian; The Script performs.

Ashton Kutcher, Aubrey Plaza, Neon Trees

Larry King, Shannon Woodward

Russell Brand stands in as guest team captain, with Sway, Hugh Fearnley-Whittingstall, Rachel Stevens and Greg Davies also appearing.