Annie begins her first deep cover operation completely on her own. Meanwhile, Auggie, Joan, Arthur and the rest of the CIA manage the fallout from Annie’s "death" at Calder’s hands.

When a financial consulting company CEO is poisoned to death, a woman from Sherlock's past emerges as a possible suspect.

Dipper and Mabel find a gigantic tooth on the shores of the lake, and set out in a rowboat to find out where it came from.

Meredith jumps back into work but finds it hard to excel at both motherhood and being a surgeon. Stephanie tries to make a good impression on Jackson's mom, and Jo finds herself overly involved with her new patient. Meanwhile, Callie and Owen deal with an emotional situation regarding a patient.

Real estate mogul Donald Trump; musical guest Selena Gomez.

Michael Rooker ("The Walking Dead") helps the team test zombie myths; more effective weapon: ax or gun; testing the strength of the living dead; outrunning or outsmarting a horde.

Kristina's campaign challenges Adam's comfort zone; Sarah and Amber try to talk about the wedding; Drew works to get closer to Natalie; Zeek gets the opportunity to provide teaching moments to his grandchildren; Crosby deals with a difficult star.

Leslie tries to calm a minor scandal that gets blown out of proportion. Tom tries to impress a new love interest, while Ben convinces Ron to prepare a will.

As Thomas Shelby prepares to oust Billy Kimber, hidden secrets are revealed and the family have to face up to the problems that have divided them. Meanwhile, Campbell, obsessed with taking down the Peaky Blinders, unleashes one last plan to destroy them.

After spending a childhood safely hidden away in a monastery, a teenage Mary Stuart arrives in France where she has been sent to secure Scotland’s strategic alliance by formalizing her arranged engagement to the French King’s dashing son, Prince Francis. Further complicating things is Bash, Francis’ handsome, roguish half-brother and Francis’ mother, Queen Catherine. When the strong-willed Queen learns of a prophecy that marriage to Mary will cost Francis his life, she is determined to save her son, no matter how many others have to pay with their lives.

A Midwestern mom hires Pope & Associates under mysterious conditions that lead to a very dangerous situation. Meanwhile, Fitz and Mellie admit their true feelings for each other.

Sheldon must decide how much "Amy time" is too much after she takes a job at his university, and their relationship is put to the test. Meanwhile, Howard finds himself sleeping on Raj's couch after a fight with Bernadette.

From "Mom", actress Allison Janney; from "Better Living Through Chemistry", actor Ben Schwartz.

When Elena and Katherine have the same dream that Stefan is in danger and desperately needs their help, they convince Damon to help them find Stefan. However, their plans are thwarted by a mysterious young woman named Tessa who seems to know everything about Stefan's history. In flashbacks to a distant time and place, Tessa reveals the shocking secrets in her past and what she has planned for the future. She also has a disturbing message for Damon about his own future. Silas forces an unwilling accomplice to help him search for Katherine, leading to a confusing and life-threatening situation for Matt. Finally, Silas reveals the reason he's determined to find Katherine, and Damon and Elena face a disturbing new reality.

Neal tries to clear Peter's name when he is charged with the murder of Senator Pratt.