Read spoilers at your own risk! For more on Wetpaint Entertainment's philosophy on spoilers, click here.
Mark is chief: Forget love triangles — Mark (Eric Dane) will "step in as chief for the day" in this episode! Apparently he takes his authority "very seriously," and "butts heads with Richard Webber [James Pickens Jr.] over a patient's liver transplant."
Owen and Cristina drama, still going strong: While Mark handles his duties for the day, Owen (Kevin McKidd) is busy being grilled about the "intimate details of his affair" by Cristina Yang (Sandra Oh). That sounds fun.