Season 6 Episode 5

Title: Invasion
Air Date: October 15, 2009 at 12:00 AM PDT

The residents of Seattle Grace and Mercy West vie for surgeries — and their careers — as day one of the hospital merger begins. However, not everyone is in competition: Arizona stands by an enraged Callie when her father, Mr. Torres, employs a priest to convince his daughter to date men, not women.