Gibbs has to put his personal feelings aside and work with Trent Kort who returns in order to track down a dangerous criminal.

The American Idol finalists take the stage to perform live for the nation. The contestants will sing their hearts out in hopes of winning America's vote and surviving another week in the competition. Tune in to see who impresses the judges and who buckles under the pressure.

Liam displays his dark side to Naomi, who is stunned but captivated by the intense, handsome bad-boy. Meanwhile, Annie spends a drunken evening under the stars with fellow thespian Max.

The fourth round of performances has led to two more contestants being released.

A challenge featuring NASCAR's Clint Bowyer has the contestants pulling cars which have been filled with extra weight assigned by their teammates. Later, all the teams are dissolved and the players will now all be on their own. Also, a player sets a record for the most weight lost at the weigh-in.

What killed the mammoths? Near the end of the last ice age 13,000 years ago, these mighty beasts disappeared from North America together with some 35 other groups of mammals, including giant ground sloths, saber-tooth cats, and American lions. For four decades, debate has raged over the cause of their abrupt demise. In Last Extinction, NOVA presents an exclusive in-depth investigation of a bold and controversial new hypothesis, which suggests that a massive impact from space could be the culprit. According to the theory, an incoming comet broke up over North America in a devastating series of explosions, causing widespread forest fires and wiping out plants, animals, and prehistoric people. The evidence comes from a mysterious black mat layer discovered at more that fifty sites across the continent. The black mat contains exotic materials including rare microscopic nanodiamonds that are claimed to be the signature of an extraterrestrial impact. But other scholars question the evidence and argue that ancient hunters armed with a lethal stone weapon the Clovis spear point drove the giant beasts into oblivion. Still others believe the unstable climate at the end of the Ice Age was responsible. NOVA explores the dramatic new evidence of a cosmic explosion and the possibility that all three explanations may be correct.

Sam, Sock, and Ben turn to Tony for help when an escaped soul leaves her baby behind. Morgan lets slip to Andi that Sam is really the Devil's son.

Jane and the CBI track down a man, who hypnotizes people into doing his dirty work for him.

Tony loses all control of his anger when Simon and his group jump into the competition for the beer account that Sarah worked so hard to bring to the company, which leaves her feeling torn between the two teams. While Conner works on the bum assignment of making a birthday video for Tony, he unwittingly discovers an interesting office secret.

While Detective Murdoch and Crabtree go to the scene of a crime, they see a man who, by all accounts, is the one who committed the crime. As they chase him, Murdoch falls from a ladder and injures himself. He needs to stay in bed. Enid and Julia vie for his attention as they try to make him comfortable. Murdoch is sure he is hearing people hitting the walls but every time he gets up he sees nothing. While Murdoch is recuperating, Crabtree gets a promotion and investigate the murder of a man. The only witness seems to be his parrot which repeats the same name over and over.

In a continuation of last season's cliffhanger, Bobby and Elsa decide to call off their wedding, and Bobby goes on the honeymoon trip alone. Back in Chicago Andy and his wife have a new baby, and the guys are having a moustache growing contest. Against Stephanie's advice P.J. decides to tell Bobby how she feels about him.

Detective Munch investigates the brutal rape and beating of a young mute girl, but things become tricky when her drawing of the devil who attacked her resembles a local priest who may not be practicing his beliefs according to canon.

The team believes that the past of a missing psychologist's brother might have played a role in his disappearance. Martin's relationship with Kim takes a spicy turn.

Mason receives an unfavorable evaluation at work, causing an angry outburst and Tony to hire a corporate therapist to help the group through a number of issues. Meanwhile, Sarah finds her new relationship blossoming and seeks the blessing of her ex-husband, only to discover the brutal truth of why he divorced her.

Toby and Oz intervene in the case of Daniel, a boy from the streets that could be involved in a series of burglaries to drugstores. Determined to help him, Toby tries to come closer to him by telling him some of his own personal experiences. But as Toby is approaching to the truth on Daniel, he discovers that the things can be more complicated than what he thought of since the life of a missing girl called Lisa is on the line.

Trevor Hale is Cupid. He was sent from Mt. Olympus to help 100 couples get together. In this pilot episode Trevor is trying to help Dave find his dream girl, without his bow and arrow, but he does have the help of his psychologist Dr. Claire Allen who isn't sure if Trevor is for real or not.

Actor Seth Rogen talks about his latest movie "Observe and Report"

Tonight Stephen welcomes the editor for slate.com and author of Good Book: The Bizarre, Hilarious, Disturbing, Marvelous, and Inspiring Things I Learned When I Read Every Single Word of the Bible, David Plotz.

When some traveller children enrol at the school problems break out. Rose's problems continue to grow. Janeece's boob job is the talk of the school.

The teams are set the challenge of creating catering businesses in London to cater for the professionals working there. At the end of the show one of the candidates from the loosing team is fired by Sir Alan.

Charlie Brooker sets his satirical sights on news and current affairs. In charting the rise of the public's role in making the news via vox pops and mobile phone footage, Brooker examines the good, the bad and the absurd in citizen journalism. Plus, reviews of two big stories making the news, controversial authored pieces, a poem and much more.