Physical Attraction... Chemical Reaction Season: 4 Episode: 407 

(Original Airdate: 11/8/07) George and Izzie's romantic chemistry is put to the test, Mark develops a crush on a fellow surgeon, and Callie's role as Chief Resident is in jeopardy.
कीवर्ड्स: grey's anatomy, season 4, full episode, spoilers, news, लेख, season 3, izzie