<P> Yang meets Owen Hunt (Kevin McKidd), an army trauma surgeon, when he patches her up from being stabbed in the stomach by a falling icicle . The pair are immediately attracted to each other and share a brief kiss . After Owen Hunt is honorably discharged, he is hired as Seattle Grace's chief of trauma surgery and he and Yang begin a flirtation . Yang grows emotionally when she decides to support Meredith in her relationship with Derek Shepherd (Patrick Dempsey), despite her logical misgivings about their staying power, and begins to be more emotionally open towards Hunt . However, Hunt has repressed memories of his time in Iraq and PTSD which causes Hunt to behave erratically, and attack and strangle her while asleep . Yang attempts to be emotionally supportive, but ends their relationship as she is afraid of sleeping next to him . Cristina loses her shot at being the first resident to perform a solo surgery despite being unanimously chosen by the attending surgeons, having been disciplined from failing to report the irresponsible behavior of the new interns . Meredith and Cristina have a fight during the intern scandal, and Cristina chooses Alex to be her replacement . They eventually reconcile . When Izzie Stevens discovers her life - threatening cancer, Yang is the one she confides in over her other friends due to Yang's ability to remain emotionally distant . Yang saves Izzie's life by coming up with a treatment plan and forcing Izzie to tell their friends of her diagnosis . Hunt begins seeing a therapist, and Yang confesses her love for him . The pair begin a tentative relationship, hampered by Hunt's therapeutic progress and his hot and cold professional behavior, wherein he frequently ignores or penalizes Yang to avoid the appearance of favoritism . </P> <P> Hunt hires ex-colleague from the Army, Teddy Altman (Kim Raver), to become the chief of cardio - thoracic surgery as a "gift" for Yang, after she breaks down over having no new head of cardio . Yang is unimpressed with Altman, neither published nor famous, but her calm proficiency and belief in Yang's skills win her over . A conflict arises in the trio due to Altman and Hunt's repressed feelings for each other . Altman chooses to resign her place as temporary head of cardio because of her feelings for Hunt . Devastated by the blow to her education and the depressing potential of returning to her previous directionless state, Yang begs Altman to stay and teach her, offering Hunt to Altman in exchange . Altman intellectually understands Yang choosing her gift over a man and their relationship is repaired, but Hunt is very hurt that Yang would trade him away . Hunt subconsciously tries to sabotage Yang's education and the two break up again after Hunt is unable to decide between the two women . Cristina saves Derek's life with a gun to her head after he is shot by Gary Clarke, a grieving widow who commits mass murder at the hospital . Hunt is injured by the same shooter after he chooses to return for Yang over Altman, and Grey treats him as Yang saves Grey's husband . Following the attack on the hospital, Hunt and Yang impulsively decide to get married . Yang is suffering from severe PTSD and is unable to bear being alone, making marriage to Hunt, who understands what she's going through, attractive . Yang spends the early days of her marriage in shock and hiding at Meredith's . </P> <P> Due to having severe PTSD and being unable to do her job correctly anymore, Cristina quits and begins bartending and eventually throws a housewarming party . Derek helps Cristina emotionally and she ultimately decides to go to work after helping the victim of a school shooting . Yang discovers she is pregnant with Hunt's child, and decides to get an abortion . Though Hunt accompanies her to the abortion, he is extremely angry with her decision . Yang then operates on Henry Burton (Scott Foley), Altman's husband, unknown of his identity . When the surgery fails and he dies, Yang is guilt stricken upon learning of her patient's identity . Altman forgives Yang and forces Yang to realize that she did everything possible . Altman's mentorship of Yang is punishing at times, and Altman brutally emphasizes that Yang must learn patience, compassion, and the basics over the flashy surgeries Yang prefers . Altman's tutelage is successful, and Yang evolves into an aware and well - rounded surgeon because of it . Altman allows Yang to come up with a wish list of dream surgeries to fulfill before Altman resigns and moves on . </P> <P> Yang and Hunt distance themselves from each other as they keep fighting over the abortion, despite attending marriage counselling . Hunt has a one - night stand with a patient's friend, leaving Yang heartbroken . She decides to move on, unsure of her future with him . As the end of the fifth year of residency is near, the surgical residents, including Yang, prepare for their medical boards and for the different fellowships they plan on joining . After she passes her exams, Yang reconciles with Hunt and tells him she is leaving Seattle for the Mayo Clinic, Minnesota . Afterward, Yang, Meredith, Shepherd, Arizona Robbins (Jessica Capshaw), Mark Sloan (Eric Dane), and Lexie Grey (Chyler Leigh) are involved in an aviation accident while on the way to Boise, Idaho to perform surgery on conjoined twins . Lexie dies, and Mark later succumbs to his injuries after they are rescued and dies . Following their rescue, Yang, traumatized, suffers from brief reactive psychosis which provokes violent outbursts and makes her unresponsive . Yang leaves Seattle to become a cardiothoracic surgical fellow and goes, as planned, to the Mayo Clinic, but has difficulties adapting to her new colleagues' way of working . While in Minnesota, Yang develops a friendship with a near - retirement cardio surgeon, Craig Thomas (William Daniels). She mainly teases him with comments regarding his old age . She also begins an affair with the head of surgery Dr. Parker (Steven Culp) who has issues with Thomas . After Thomas dies from a heart attack, Yang returns to Seattle . </P>

When does cristina yang come back after quitting