 Derek and Meredith try to be discreet as they spend the night together at Meredith s house, but their haggard appearance speaks volumes to Bailey, who warns Meredith to end the relationship. Meanwhile, George suspects an anesthesiologist of drinking on the job, Alex treats a former competitor who now finds honor in self-mutilation, Izzie has to deal with a patient who won t let his girlfriend go, literally, and Cristina battles a case of what seems to be the flu.