Izzie (Katherine Heigl) gets fired from Seattle Grace and believes that Alex had caused her to lose her job. She leaves him, later returning after learning that he never did anything to her. She's free of cancer, and Alex is happy for her. Still, he decides to break things off between them for good, realising that he deserves better. This prompts Izzie to permanently leave Seattle. Her arc feels fizzled out right after her emotional cancer diagnosis throughout season five. At least Alex gets closure, right?