Sherlock tries to determine who has been killing weak and terminal patients at a hospital, making it look like they died of natural causes. Meanwhile, Sherlock learns more about Joan’s decision to walk away from her surgical career.

Charlie and Dee become romantically involved with two members of a wealthy family, which arouses jealousy in Mac, Dennis, and Frank.

Musicians Steven Tyler and Joe Perry; actress Judy Greer; musical guests Aerosmith; a Top Ten List presented by Vice President Joe Biden

Reese must surreptitiously protect an investigative reporter without becoming a part of her story.

It's a big day for Mimi Maguire - it's her first wedding anniversary to Billy and they're going to renew their vows. Determined to make a fresh start, Mimi sets about throwing away memories of her past life with Paddy, but she alienates a furious Ruby with her comments about her dad.

A game threatens Sheldon's relationship with Stephen Hawking; Penny secretly signs up for a college class.

Michael Bloomberg issues post-Sandy travel mandates, Mitt Romney sways Billy Graham on Mormonism, and music marvel David Byrne teams up with St. Vincent.

From "Community", actor Joel McHale; chef Alton Brown.

Kevin and Jenny realize that Kristin Cavallari is in their baby group. Meanwhile, Rafi is entrusted to take Ruxin's son to his swim class.

Damon goes with Elena and Bonnie to visit Whitmore College, where Professor Shane is taking over the Occult Studies classes formerly taught by Bonnie’s grandmother. At a fraternity costume party, Damon takes advantage of the wild scene to give Elena a lesson in choosing a victim. Rebekah’s attempt to buy Matt’s forgiveness falls flat, but she is intrigued by unexpected news from Klaus. When Stefan questions Klaus about Connor’s motives, Klaus reveals a long-ago encounter with a powerful group of vampire hunters, but it’s Rebekah who delivers the information that stuns Stefan.