The season continues the story of a group of surgeons and their mentors in the fictional Seattle Grace Hospital, describing their professional lives and the way they affect the personal background of each character.Season four had twelve series regulars with ten of them returning from the previous season, out of which eight are part of the original cast from the first season.
boss Shonda Rhimes hinted that more departures could be on the horizon following last May’s deadly cliffhanger — and she wasn’t kidding. Mark Sloan looked on in horror as his soul mate Lexie (Chyler Leigh) passed away from her own injuries suffered in the plane crash, has , ABC and Shondaland for the experience and memories I have had over the course of this run,” Dane tells TVLine exclusively.
Addison Montgomery and aired on September 19, 2007, before the season premiere.
The season was officially released on DVD as a five-disc boxset under the title of Grey's Anatomy: Season Four – Expanded on September 9, 2008 by Buena Vista Home Entertainment.
In 1999, Leigh and her mother relocated to Los Angeles in order for Leigh to develop a career in acting.
At age 16, Leigh took and passed the California High School Proficiency Exam.