"Fear (Of the Unknown)" is the twenty-fourth episode and the season finale of the tenth season of the American television medical drama Grey's Anatomy, and is the 220th episode overall. It aired on May 15, 2014 on ABC in the United States. The episode was written by Shonda Rhimes and William Harper and directed by Tony Phelan. On its initial airing, it was watched by 8.92 million viewers. The episode marked the departure of one of the lead characters, Cristina Yang, played by Sandra Oh since the inception of the series. The episode focuses on Yang as she prepares to say her goodbyes to the doctors at Grey-Sloan Memorial hospital, including her "person" Meredith Grey (Ellen Pompeo), her long-time friend and Meredith's husband Derek Shepherd (Patrick Dempsey) and her love-interest Owen Hunt (Kevin McKidd) and leave for Zurich for her new job at the Klausman Institute for Medical Research. The episode received widespread critical acclaim with high praise directed towards Oh's performance.
Amidst Yang's departure a catastrophe occurs at a nearby mall bringing loads of patients to Grey-Sloan. Derek asks Meredith to move to D.C. with her for his new job. Callie Torres (Sara Ramirez) and Arizona Robbins (Jessica Capshaw) consider having a surrogate mother carry their child while April Kepner (Sarah Drew) is nervous about raising her own child with Jackson Avery (Jesse Williams). Miranda Bailey (Chandra Wilson) is nominated for a position at the Hospital Board to replace Cristina, who instead left the seat for Alex Karev (Justin Chambers). Also, Leah Murphy (Tessa Ferrer) is fired from her job, Shane Ross (Gaius Charles) quits his residency at Grey-Sloan to accompany Yang to Zurich as her student and Richard Webber (James Pickens Jr.) meets with Maggie Pierce (Kelly McCreary), and finds out that her birth mother was Ellis Grey (Kate Burton).
This episode marks the final appearance of Sandra Oh as Cristina Yang and Gaius Charles as Shane Ross. It is also the final appearance of Tessa Ferrer as Leah Murphy as a series-regular.
Plot
The day has arrived that Cristina leaves for Zurich, but a possible act of terrorism delays her departure. Cristina needed to run to the mall, Derek was passing around D.C. brochures, and Alex was looking to buy a fancy car with all his new money. The foundation was cutting funding and Bailey’s genome lab was going to be shut down. Before Yang could get to the mall to buy a European phone charger, an explosion at the mall sends multiple injured victims to the Grey Sloan Memorial Hospital. Leah comes to the ER when she hears about the explosion, but leaves with no goodbyes when she sees every patient had been treated.
April told Hunt that she was pregnant, a happy announcement that was interrupted by some not-so-happy news. April receives a pep talk from Catherine Avery, her mother-in-law, when she starts to fear raising a baby in a world that is so dangerous. With all hands on deck, the hospital turned into a zoo filled with decontamination zones, and thankfully, one Cristina Yang. She hadn’t had time to get to the mall, so instead, she came in to lend a hand, as did Leah. Cristina, looking for closure, can’t leave the hospital until she and Meredith dance it out one last time. Shane demands that he take control of his education and leaves to work under Cristina in Zurich.
In surgery, Cristina asked Alex if he really wanted to go the private practice route. She told him he had good hands, he thinks fast, and he acts faster. With only two hours until her flight, Cristina was scrubbing in to do Link’s heart transplant surgery, but Meredith told her it was time to go. Cristina found Bailey and Webber they both had to say goodbye to Yang, but not before Shane got a word in. He asked Yang to take him with her to Switzerland. He was in charge of his education and he chose Yang. She was who he wanted to learn from, and she agreed. Cristina told Meredith to wait for her, and she ran to the OR where Owen was operating. Cristina knocked on the gallery glass, and when he looked up, she waved.