This two-episode disaster kicks off the eighth season of the show and follows the doctors as they deal with a massive sinkhole that has opened up in the centre of Seattle. While this obviously leads to some tricky medical cases, including Callie and Owen's attempt to talk a man trapped at the bottom of the sinkhole through cutting off his wife's leg, most of the lasting drama in these two episodes is unrelated to the disaster itself, with Meredith temporarily kidnapping Zola, everyone turning on Alex after he reveals Meredith tampered with Derek's clinical trial, and Jackson being crowned the "Gunther," a title given to a resident who rises to become a natural leader during a high-pressure situation.