Season seven of "Grey’s Anatomy" draws to a dramatic close tonight, and although there aren't any crazed gunmen in sight, the staff of Seattle Grace are nonetheless in for some life-changing events.As word spreads that Meredith (Ellen Pompeo) tampered with Derek's (Patrick Dempsey) Alzheimer's trial, Alex (Justin Chambers) gets a leg up in the race for chief resident.Meanwhile, Cristina (Sandra Oh) finds herself in a compromising situation, forcing her to decide between her career and her relationship. (ETonline.com)