- Season 1 Episode 9
Who's Zoomin' Who?
An outbreak of a sexually transmitted disease affects several members of the hospital staff, prompting Chief Webber to call a meeting. Meanwhile, the chief reluctantly confides to Dr. (Derek) Shepherd about his own medical concerns; Izzie and Cristina are worried by a patient's wife and daughter who are at odds over his care; Burke treats Bill, a college buddy whose medical diagnosis raises some questions regarding his wife's actions; and, just as Meredith and Derek grow more intimate, a bombshell is dropped
Ellen Pompeo as Meredith Grey
Patrick Dempsey as Derek Shepherd
Sandra Oh as Cristina Yang
Isaiah Washington as Preston Burke
Katherine Heigl as Isobel "Izzie" Stevens
Justin Chambers as Alex Karev
T.R. Knight as George O'Malley
Chandra Wilson as Miranda Bailey
James Pickens, Jr. as Richard Webber.
Kate Walsh as Addison
Lauren Bowles as Alice Franklin
Wayne Wilderson as Bill Adams
Wendy Davis as Holly Adams.