Stephen Gabriel

Derek and the attendings go out to celebrate when he gets the grant he needs for his clinical trial; Meredith and Alex must fend for themselves during the night shift.

A promising student wakes up to the hangover from hell when he is found wandering the streets covered in blood and wielding an axe. As the investigators attempt to piece together the night's events, Flack struggles to keep his cool and Mac develops a bond with the suspect.