The episode opens with a voice-over narration from
Cristina Yang (
Sandra Oh) about facing the unpredictability of life and choosing courage over fear in the face of the unknown. The day finally arrives for Cristina to leave for
Zurich,
Switzerland, but her departure is delayed by a potential act of
terrorism. Cristina plans to make a quick stop at the mall to buy a European phone charger, while
Derek Shepherd (
Patrick Dempsey) is busy handing out brochures for
Washington, D.C., and
Alex Karev (
Justin Chambers) is contemplating buying a fancy car with his newfound wealth. Meanwhile,
Miranda Bailey's (
Chandra Wilson) genome lab faces closure due to funding cuts by the foundation. Just as Cristina is about to head to the
mall, an explosion occurs there, sending multiple injured victims to Grey Sloan Memorial Hospital. Leah Murphy (
Tessa Ferrer) returns to the ER upon hearing of the explosion, but leaves without saying goodbye after realizing all the patients have been treated. In the midst of the chaos,
April Kepner (
Sarah Drew) tells
Owen Hunt (
Kevin McKidd) that she is pregnant, but their joy is interrupted by grim news. April receives reassurance from Catherine Avery (
Debbie Allen), who gives her a pep talk about raising a baby in an increasingly dangerous world. The hospital turns into a frenzy, with decontamination zones set up for the explosion victims. Cristina, who hadn't made it to the mall, returns to help with the crisis, as does Leah. Cristina, feeling the weight of her departure, realizes she can't leave until she and
Meredith Grey (
Ellen Pompeo) have one last "dance it out". Shane Ross (
Gaius Caesar) also approaches Cristina, declaring his desire to follow her to Zürich and continue learning under her. During surgery, Cristina asks Alex if he truly wants to pursue private practice, reminding him of his surgical talent and quick thinking. With only two hours until her flight, Cristina prepares to assist in Link's heart transplant surgery, but Meredith steps in, telling her it's time to leave. Cristina bids goodbye to Bailey and
Richard Webber (
James Pickens Jr.), and agrees to take Shane with her to Switzerland, after he insists she is the one he wants to learn from. Cristina rushes to the OR gallery where Owen is operating, knocks on the glass, and waves a silent farewell. Outside, Link's new heart arrives in a cab, but Meredith insists that Cristina get in the cab and go. When Cristina hesitates, Meredith reminds her that she loves her and urges her to leave now or risk never going. After their emotional exchange, Cristina grabs Meredith and pulls her into an on-call room for one final "dance it out". As Meredith finds a song, Cristina gives her parting advice: to call at least twice a month, to mock Alex regularly to keep him from becoming insufferable, and to take care of Owen. Cristina ends with a heartfelt plea: "Don't get on little tiny planes that can crash, or stick your hand in a body cavity with a bomb, or offer your life to a gunman. Don't be a hero. You're my person. I need you alive. You make me brave." They dance it out one last time before Cristina departs. Meanwhile, Meredith tells Derek that she can't leave
Seattle—the place where she has built her life—and decides she won't move to D.C. with him, despite his wishes.
Callie Torres (
Sara Ramirez) and
Arizona Robbins (
Jessica Capshaw) consider having a
surrogate mother carry their future baby after treating a surrogate injured in the explosion. In the aftermath of Cristina's departure, Webber nominates Bailey for a position on the board, but it's revealed that Cristina left Karev her shares of the hospital and her board seat. Webber connects with Dr.
Maggie Pierce (
Kelly McCreary), the new head of
cardiothoracic surgery, and discovers that her birth mother was Ellis Grey (
Kate Burton). ==Production==