Shonda Rhimes the creator, head writer, and executive producer of the ABC medical drama Grey's Anatomy, recently announced on her official twitter page that Summer Glau will make an guest appearance in an episode of the show.
Love table read days! We have Summer Glau as a guest star!
Summer will appear in Episode 16 of Season 8 according to tvguide.com which began production with a table read Monday, 23th January. The episode will air in February.
More info about the show and Summer's Character can be found here: GA wiki page
Excerpt from online articles reporting the news can be found here: Press Reviews