Season: 7

Meredith, looking to prove she is Chief Resident material, learns that anything and everything can happen in an hour's time when she steps up to run the ER for a night; meanwhile, Bailey sneaks off with Eli and gets into a little mischief, and everyone is surprised when the Chief's wife, Adele, shows up as one of the ER patients.

Thatcher Grey, Meredith and Lexie's father, returns to Seattle Grace with stomach pains and a new, twenty-something tattooed girlfriend, Danielle. Meanwhile, Alex clashes with the new OB, Dr. Lucy Fields, over a patient and Mark places Jackson on his service in exchange for information on Lexie.

Derek breaks ground on his Alzheimer's clinical trial and Meredith can't help but feel left out; Bailey's attempt to take the hospital into the age of new media with live tweets from the OR does not go over well with the Chief; and Callie, Mark and Arizona must learn to navigate through the pregnancy together, which starts off with Callie driving her new obstetrician crazy.

Derek breaks ground on his Alzheimer's clinical trial and Meredith can't help but feel left out; Bailey's attempt to take the hospital into the age of new media with live tweets from the OR does not go over well with the Chief; and Callie, Mark and Arizona must learn to navigate through the pregnancy together, which starts off with Callie driving her new obstetrician crazy.