Guest Appearances

Ted surprises Lily, Marshall, Barney and Robin with a stylish New Year's Eve excursion around New York.

The staff tries to deal with physical and emotional trauma in the wake of the vengeful gunman's deadly rampage; Derek makes a spontaneous decision to resign as chief and return to surgery.

Meredith finally tells Derek about her pregnancy and miscarriage; during a surgery, Cristina experiences PTSD; Bailey won't let Alex operate until he has the bullet in his chest removed.

Everyone tries to help Callie and her baby recover; the sudden death of a clinical trial patient impacts Derek and Meredith in different ways; Teddy is surprised by a familiar face.

Issues surface when Derek's estranged sister, Amelia (Caterina Scorsone), visits unexpectedly; Meredith and Derek continue to try to ease Cristina back into surgery.

Meredith's dishonesty is revealed, leading to unexpected consequences for her and others; Cristina is forced to choose between her relationship and her career; the new chief resident is chosen.

Callie and Arizona's wedding is not coming together as they hoped it would; Alex seems to be the first choice for chief resident; Meredith and Derek make a life-changing decision; Dr. Perkins tempts Teddy with a proposition.

Work and personal pressures leave Meredith on edge; formal interviews for the chief resident position begin; Lucy and Alex's relationship is tested.

Lorelei is stunned to hear Rory's plans for the future and turns to Richard and Emily for help, but soon realizes that Luke is the only person she can trust.

Faces from the past show up in the Hamptons, bringing with them different kinds of trouble for Emily and Victoria; Jack's sense of duty increases; Padma makes a move that could affect Nolcorp.

Amanda and Jack's wedding stirs up emotions as Emily thinks about what might have been; Daniel faces complications at Grayson Global; Conrad starts a new chapter.

Jack is suspicious when Conrad and Victoria start a charity in Amanda Clarke's name; once again, Emily's past catches up with her.

Emily and Victoria pull out all stops as they work to destroy each other.

When Emily's blackouts become increasingly violent, the only person who can help her is the one she betrayed the most; Victoria tries to deal with someone from the past.

Emily Thorne rents the Southampton home she once shared with her father and sets her plan in motion.

Emily gets to work on her next target, a former family friend who testified against her father; Victoria tries to find more information on Emily.

With help from her new ally, Emily seeks to destroy the district attorney who convicted her father; grieving Victoria tries to confirm her suspicions about Emily's past.

Recent scandals leave the Graysons on edge; Emily targets the psychiatrist responsible for institutionalizing her as a child; Declan and Jack face a tough decision.

Emily intends to finally follow through with her plan for revenge; the Graysons continue down a path of self-destruction; an explosive event changes everything.

Victoria's vulnerabilities are exposed when feelings of guilt and a fight with her daughter become too much to bear; a vindictive Lydia returns; now aware that he has been betrayed, Daniel decides to make a major change.