[s6e5] Invasion -

The fifth episode of the sixth season of , titled " Invasion ," is a pivotal hour centered on the high-tension merger between Seattle Grace and Mercy West hospitals. Originally aired on October 15, 2009, it marks the introduction of significant new characters and a major departure for a long-time series regular. Plot Summary

: Seattle Grace residents are forced to compete for surgeries and equipment with their new rivals. Tensions boil over when Reed Adamson attempts to take George O'Malley's old locker, leading to a confrontation with Izzie Stevens.

: Callie Torres faces a personal crisis when her father, Carlos, returns to the hospital with a priest in a misguided attempt to "cure" her bisexuality. [S6E5] Invasion

: The episode was written by Mark Wilding and directed by Tony Phelan .

: This episode served as the first half of a crossover event with the spin-off Private Practice . The storyline of the patient Izzie endangered, Sarah Freemont, concludes in the Private Practice episode "Right Here, Right Now". The fifth episode of the sixth season of

: In one of the show's most controversial turns, Izzie makes a critical medical error during a dialysis treatment that puts a patient's life at risk. Due to the hospital's budget cuts and her mistake, Chief Webber fires her, leading her to leave Alex Karev with nothing but a letter.

: Meredith Grey remains largely sidelined in a hospital bed throughout the episode, a creative choice made to accommodate actress Ellen Pompeo’s real-life maternity leave; the character is written as having just donated a portion of her liver to her father. Production and Impact Tensions boil over when Reed Adamson attempts to

The "invasion" refers to the arrival of residents from Mercy West, including , Jackson Avery , Reed Adamson , and Charles Percy . The episode portrays a literal battle for space and patients: