As the newcomers enter their second year of internship, their initial curiosity and passion are replaced by busyness and fatigue. They also slowly discover that Dr. Bailey, who is rumored to be a "Nazi," has an extremely kind heart under his harsh appearance. Meredith (Ellen Pompeo) and "Dream Man" Derek (Patrick Dempsey) develop from a one-night stand to a love affair, but unexpectedly, "the legal wife" Addison (Kate Walsh) appears. It turns out that Derek is currently separated from his wife. The marriage problems that he has been avoiding are put on the table again, and Meredith is suffering; on the other side, the sparks between Christina (Sandra Oh) and the black doctor Burke continue to grow. She struggles between "pregnancy" and "career", but unfortunately suffers a miscarriage; Isobel (Katherine Heigl) and Alex (Justin Chambers) start dating, and the development is not smooth...