[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

: 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

: 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. The fifth episode of the sixth season of