Invasion (Grey's Anatomy)

"Invasion"
Grey's Anatomy episode
Izzie Stevens trying to fight Reed Adamson, as the latter wants to take George O'Malley's old locker.
Episode no.	Season 6 Episode 5
Directed by	Tony Phelan
Written by	Mark Wilding
Featured music	"Clap" "I Want You Now" "Your Ghost"
Original air date	October 15, 2009 (2009-10-15)
Running time	43 minutes
Guest appearances
Robert Baker as Dr. Charles Percy David Bowe as Don Sarah Drew as Dr. April Kepner Alexie Gilmore as Sarah Freemont Jesse Williams as Dr. Jackson Avery Nora Zehetner as Dr. Reed Adamson Freda Foh Shen as Missy Grant Bruce French as Father Kevin Héctor Elizondo as Carlos Torres
Episode chronology
← Previous "Tainted Obligation" Next → "I Saw What I Saw"
Grey's Anatomy season 6
List of episodes

"Invasion" is the fifth episode of the sixth season of the American television medical drama Grey's Anatomy, the show's 107th episode overall, and the first of a two-part patient crossover event with Private Practice. It was written by Mark Wilding and directed by Tony Phelan. The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on October 15, 2009. In the episode, the physicians of Seattle Grace Hospital must learn to co-operate with new Mercy West residents, who do not act in a kind manner to them. Other storylines include Dr. Callie Torres (Sara Ramirez)'s father returning to the hospital to condemn her bisexuality, and Dr. Izzie Stevens (Katherine Heigl) putting her career into jeopardy after administering the wrong treatment to a patient.

The episode was Heigl's last appearance before her five-episode hiatus to film a movie. It is set in a fictional hospital in Seattle, Washington. Héctor Elizondo returned as a guest star, while Sarah Drew, Jesse Williams, Nora Zehetner and Robert Baker made their first appearances. "Invasion" received positive reviews, with critics praising Drew's, Heigl's, Jessica Capshaw's, Ellen Pompeo's and Sandra Oh's performances. Upon its initial airing, the episode in the United States was viewed by 13.79 million people, garnered a 5.0/13 Nielsen rating/share in the 18–49 demographic and ranked third for the night in terms of viewership

The patient Sarah Freemont (Alexie Gilmore)'s life hangs in the balance after Izzie's dialysis error. Her arc concludes in the second-half, a Private Practice episode titled "Right Here, Right Now", which sees Miranda Bailey (Chandra Wilson) fly Freemont to Addison Montgomery in LA for help.