Now that Bailey is aware of Meredith and Sheppard's procedural relationship outside the hospital, things are a bit tense. While Bailey won't give this duo up, she will make life difficult if Meredith is afforded any special treatment. As a result, Sheppard is extra harsh to Meredith in public.
Alex, conversely, is being unusually kind to a woman named Annie with a 70-pound tumor. He's about to scrub in for surgery with Dr. Burke until the patient overhears Alex making disparaging remarks about her during an MRI. Subsequently, Cristina and George are left with the supposed honor of holding up the tumor during surgery. Alex and Izzie are therefore left on rounds, but the former leaves Izzie alone as he laments the decision to keep him away from the procedure.
Annie ends up dying on the table and Alex seems to regret his attitude toward her. Meredith is also sorrowful for thinking badly of how Sheppard treated her. He ends up supporting his favorite intern/lover after she convinces a patient with Parkinson's Disease to seek a certain treatment in order to make it down the aisle for his daughter's wedding.
After Annie dies, Cristina is left in physical and emotional pain. Burke finds her and an initial awkwardness is soon replaced with another sexual romp.