In "In the Midnight Hour," from Season Five of Grey's Anatomy, Meredith and Cristina must respond to a surgical crisis. Then again, that happens most weeks.
Added:
In "In the Midnight Hour," from Season Five of Grey's Anatomy, a surgery goes wrong and Lexie finds herself in crisis mode.
Added:
It's a big operation that goes wrong in "In the Midnight Hour."
Added:

Grey's Anatomy Season 5 Episode 9 Quotes

Page the Chief, and go get Bailey. Tell him there's been an emergency. You're not to say anything else. And take that crazy look off your face!

Meredith

Lexie: Shall we call a code?
Cristina: There is no code on an outpatient surgery in the middle of the night because normally, this would be done by a surgeon in a regular OR.