The parents of Arizona's 10-year-old patient offer the hospital a generous donation, but Arizona finds herself in a conflict of interest when the patient's condition worsens; Cristina tests her boundaries with Owen.
Jason and the team travel to Saudi Arabia, where extremists threaten to release anthrax into an underground water supply. Meanwhile, Ray contemplates joining another team.
Despite their chaotic personal lives, the women decide to follow through with the big dinner party the late Mary Alice had planned to host.
Callen goes undercover at a prestigious high school to track down a teenaged hacker who is compromising missions.
The Lyons go to Philadelphia, where they see what their lives could have been like if Lucious hadn't been successful, another woman causes tension between Hakeem and hip-hop star Tianna.