The NCIS team must reveal the truth behind the murder of a jail guard which resulted in a prison riot and McGee being held captive by the inmates.

Brenda receives life changing news. Meanwhile, Dixon grows closer to Christina, and an unexpected secret is destined to rock Adrianna's world.

The season premiere kicks off with the contestants arriving at the ranch in teams of two, including mother/daughter, father/son, sisters, best friends, grandparents, cousins, an engaged couple and former models. Included among them are the series' oldest players yet (63-year-old grandparents), youngest male contestant (18), heaviest female contestant (379 lbs.) and heaviest contestant ever in the history of the show (454 lbs.). Alison Sweeney hosts and trainers Bob Harper and Jillian Michaels return to train the 11 couples who begin the show with a combined weight of more than 3.5 tons.

The new Chief of Medicine causes a stir at Sacred Heart, while J.D. struggles to maintain the new interns, and Elliot has issues with her ego.

J.D. and Turk make a huge sacrifice concerning a decade-long steak night tradition for a dying patient. Meanwhile, Dr. Maddox, the new Chief of Medicine, begins to show her true colors.

Bologna-making in Pennsylvania. Also: the host repairs a special toilet in Alaska.

Megan finally confronts her mother without any sugarcoating about how she really feels about being abandoned. Meanwhile, Sage and Rose plan a charity event for Cuban refugees as an excuse for Sage to spend more time with Luis. Also, Charlie goes back to school, but Mandy becomes jealous when she learns that he will be studying with Megan. Finally, Megan learns that Lily is being held in prison.

A convicted murderer convinces Jane to help prove his innocence by telling Jane that he'll give him information on Red John. Jane quits CBI to devote all of his time to getting him released.

A girl who vanished four years before, when she was 14, reappears. She says that a man held her captive as a sex slave.

Sean's physical and emotional well-being are greatly impacted after he makes it through Colleen's attack. Christian gets some disconcerting news.

A case about a missing teenager, last seen with her bipolar mother, gets twisted when the team finds she has a secret life. Jack and Sam's relationship also hits a bump in the road.

Leverage Consulting & Associates seek to take down a Serbian adoption agency that's scamming money from unsuspecting American couples.

Erin's new boyfriend comes to town and the depth of their relationship makes Whitney question the strength of her own romance with Jay. Also, Whitney searches for a place to live.

It sounds like a Hollywood blockbuster: a deadly asteroid is on a collision course with Earth. But in reality, it's only a matter of time before a giant space rock threatens to wipe out civilization. An asteroid took out the dinosaurs sixty-five million years ago. Are we next? This episode analyzes the threat and explores the many ways - from a nuclear bomb to ingenious new technology - that experts are proposing to stop Armageddon.

Author Michael Wolff talks about his new book The Man Who Owns the News: Inside the Secret World of Rupert Murdoch.

Leslie, Todd and Carl create a new grocery store bowling game using frozen turkeys. The new SuperValue Mart store manager, Mercy P. Jones, bets Leslie he can't throw 3,000 frames without leaving a single pin standing and gambling fever takes over the store.

Tonight Stephen welcomes Fortune columnist and author of The Tyranny of Dead Ideas: Letting Go of the Old Ways of Thinking to Unleash a New Prosperity, Matt Miller

Rachel finds her attempts to improve conditions at the school compromised by the arrival a gun carrying teenager and his family.