
The season followed the continuation of the surgical residency of five young interns, as they experience the demands of the competitive field of medicine, which becomes defining in their personal evolution. Although set in fictional Seattle Grace Hospital, located in Seattle, Washington, filming primarily occurred in Los Angeles, California. Whereas the first season mainly focused on the impact the surgical field has on the main characters, and the second one provided a detailed perspective on the physicians' private lives, the third season deals with the tough challenges brought by the last phase of the surgeons' internship, combining the professional motif emphasized in the first season, with the complex personal background used in the second. Through the season, several new storylines are introduced, including the arrival of Dane's character, Dr. Mark Sloan, conceived and introduced as an antagonizing presence.

Time Has Come Today
Meredith must make an important choice about which path she wants to follow to determine the future of her love life. While she considers her future she and others have flashbacks of their pasts. Cristina spends time with Burke while he recovers. Webber and Adele have a conversation after he spends the night at the hospital. Everyone attempts to deal with Izzie's choice to quit. George seeks relationship advice from Derek.

I Am a Tree
Cristina meets Burke's parents, the interns try to get Izzie's job back, and Addison takes a day off, a surgical patient may be living her last day. Some of the interns want to know why Bailey won't talk to Izzie. Meredith tries to decide between Derek and Finn and comes to a decision somewhat. Webber finds out that Callie has been living in the hospital and he confronts her about it.