The residents of Seattle Grace and Mercy West vie for their careers as the hospital merger begins; Arizona stands by enraged Callie when Callie's father employs a priest to help convince her to date men.
The residents of Wisteria Lane take stock of their lives after tragedy; Susan grows suspicious of Mike's reasons for moving to the neighborhood; Lynette reaches the breaking point in her addition to the twins' medication.
A series of freeway car accidents leads to a catastrophic overpass collapse that endangers the lives of civilians and members of the 118.
Looking back at how Chimney joined Station 118 and became the firefighter and paramedic he is today.
The hospital must keep a surrogate mother on life support until her fetuses are able to survive; Naomi discovers that Addison and Sam have feelings for each other.