Callie is facing a malpractice lawsuit filed by an Olympic athlete that was referred by Cristina. During the athlete’s hip surgery, his oxygen level dropped and his heart started beating really fast causing the team of doctors to close up without removing the last sponge. Callie's father returns to show his daughter support, and learns that Callie and Arizona are no longer together. Through flashbacks, it is revealed that Callie and Arizona had chosen a sperm donor to inseminate Arizona; they wanted a second child. However, during one of the pregnancy check-ups, their doctor couldn't find the heart beat because she had miscarried. Through the trial process, Cristina tells the jury that she had insisted working on the athlete's heart before his legs (which had been affected by a post-op infection); Callie did not agree to this sequencing, and that is why they went ahead with a second surgery on his legs. Callie’s father, in effort of saving his daughter's marriage, reveals that he once cheated on her mother and had her mother not given him a second chance, he wouldn’t have Callie. This persuades Callie to go to Arizona and ask her to move back in.