Annie travels to New York after receiving new intelligence. Elsewhere, Arthur's court date looms nearer, and Joan finds a solid lead.

Sherlock’s brother, Mycroft, arrives in New York and enlists Holmes and Watson to help solve a case involving his former fiancée. Meanwhile, Sherlock has a difficult time accepting Mycroft and Joan’s relationship.

The members of New Directions tackle their assignment of getting out of their comfort zones and determining whether they're more like "Katy" or "Gaga." Kurt holds auditions for his new band and must decide if he'll let in the overly bold performer, Starchild. Meanwhile, Jake gets closer to Bree as he and Marley grow apart.

The issues between Meredith and Cristina hit a boiling point when one of them ultimately betrays the other at the hospital. Derek tells Jackson that he needs to let go and allow the second year doctors to work on his patients, and April and Matthew make a bold decision about their relationship. Meanwhile, Bailey has difficulties with Ben’s return.

From "Live! With Kelly and Michael", talk show host Kelly Ripa; from "How I Met Your Mother", actress Cobie Smulders; musicial guest Gary Clark Jr.

Kristina tells Amber a story about her relationship with Adam; Drew falls hard for a classmate; Max finds some pictures from Hank and Sarah's past.

Mary has to decide if she is willing to lie and sentence a man to death in order to have King Henry let her out of her engagement to Prince Francis. Meanwhile, Francis and Bash are suspicious of Tomas’ true intentions which will ultimately lead to a confrontation with disastrous results.

Olivia must make a very important decision that will affect all of her relationships in the White House, and Harrison's allegiance to the Gladiators is tested. Meanwhile, the team continues to prep Josie Marcus while Cyrus and Mellie plot against her.

Sheldon feels slighted when Professor Proton (recurring guest star Bob Newhart) seeks advice from Leonard instead of him, and he seeks revenge by befriending a rival science TV host, Bill Nye (guest starring as himself). Meanwhile, Raj gets jealous when Howard crashes "girls' night."

The Senate cracks down on sexual discrimination in the workplace, Stephen is nominated for a People's Choice Award, and author Daniel Lieberman discusses "The Story of the Human Body".

From "2 Broke Girls", actress Kat Dennings; video game developer Markus "Notch" Persson.

Silas happily announces his new goal to Damon and Elena, but they are skeptical when he promises to accomplish one important task in return for their help. Tessa confidently tells Stefan about her next move, then realizes that Silas has managed to outsmart her. A desperate Katherine discovers a new and unexpected consequence of becoming human again, and realizes she needs a new place to stay. In exchange for a spot in the dorm room, she offers to show Caroline how to get answers from Dr. Maxfield. Bonnie is touched by Jeremy’s strength and determination to stand by her. Finally, Damon is stunned when he figures out the secret to Tessa’s plan.

The results of the coaches' and America's picks for the Top 12.

Peter sends Neal undercover with a psychiatrist who may be manipulating her patients into committing robberies.