"A Change Is Gonna Come" is the fourth season premiere of the American television medical drama Grey's Anatomy, and the 62nd episode of the overall series. The premiere focused on the aftermath of the main characters' promotion to residency, following the conclusion of their internship. The episode was the first not to feature Isaiah Washington, portraying Preston Burke, due to his being fired from the series at the conclusion of season 3. The episode also marked Chyler Leigh's promotion to series regular status, following her guest appearances in the last 2 episodes of the previous season. Also featured were one-time guest actors Mark Pellegrino, Stephania Childers, Sandra Thigpen, and Steven Porter. The story arcs which provided a particular focus on individual characters include Cristina Yang (Sandra Oh) dealing with the aftermath of Burke's (Washington) departure, and the dissolution of their engagement, Izzie Stevens (Katherine Heigl) struggling with her romantic feelings towards the married George O'Malley (T. R. Knight), and Callie Torres (Sara Ramirez) learning to deal with her new position of Chief Resident. Also dealt with was Alex Karev (Justin Chambers) coping with Rebecca Pope's (Elizabeth Reaser) departure, and Meredith Grey (Ellen Pompeo) facing the conclusion of her relationship with Derek Shepherd (Patrick Dempsey), while dealing with the arrival of her half-sister, Lexie Grey (Leigh), who enrolls in the surgical program at the hospital. The script for the premiere was written by series creator Shonda Rhimes, while Rob Corn served as the director. The episode aired on September 27, 2007 in the United States on the American Broadcasting Company (ABC), with an approximated 20.93 million viewers tuning in. Ranking #2 in the time-slot and #3 for the week, the episode garnered a 7.3 Nielsen rating in the 18–49 demographic, seeing a decrease from the previous episode, which received an 8.0 rating. Critical response of the episode ranged from mixed to negative, with Yang's storyline being a particular source of critical acclaim from television reviewers. Although the episode was fictionally set in Seattle, Washington, filming occurred in Los Angeles, California. Plot The episode opens to a voice-over narrative from Meredith Grey (Ellen Pompeo) about change, the episode's main theme. Following the conclusion of their internship, Meredith, along with her colleagues, Cristina Yang (Sandra Oh), Izzie Stevens (Katherine Heigl), and Alex Karev (Justin Chambers) commence their residency in the department of surgery, and start dealing with new responsibilities, including the new generation