News of Meredith's dishonesty in the clinical trial comes to light, leading to unanticipated consequences for her and others; Cristina finds herself in a compromising situation, which forces her to decide between her career and her relationship; Owen posts his decision for Chief Resident, and Teddy makes a surprising choice regarding her love life -- and her future.

The fifth-year residents return for the first day of a year that will make or break their careers: Meredith faces the consequences of tampering with Derek's clinical trial and is terminated at the hospital; April tries to step up to the plate as Chief Resident in the wake of a giant sinkhole in the middle of Seattle; and Cristina and Owen are still at odds over their drastically different feelings for their unborn child.

News of Meredith and Derek's unsteady relationship raises a red flag for Zola's adoption counselor; Alex quickly realizes that he has become the outcast of the group after ratting out Meredith; and Cristina makes a tough decision regarding her unexpected pregnancy. Also, Chief Webber brings Henry in for a last minute surgery, alarming Teddy.

This is an historic episode that finally crosses a long-standing barrier.

The residents try their hardest to impress surgical great Catherine Avery-who also happens to be Jackson's mother-when she arrives at Seattle Grace to perform a groundbreaking transplant surgery; Arizona and Alex find their hands tied with a confidentiality issue when a familiar patient comes into the ER; meanwhile, a love-struck Teddy throws a dinner party for the couples, and Bailey makes a decision regarding her love life

A severe car crash involving an entire family results in an all-hands-on situation in the ER, as the eldest daughter is left to make the toughest decision of her life. Meanwhile Teddy, still in the dark about Henry's death, calls upon Cristina to help with her patient in the O.R., and Lexie finds herself working alongside Mark's new girlfriend, Julia, during an eye surgery.